External Combustion Engine

The object of research is the air-cooling system, for F4L912 direct injection diesel engine (mounted on the bench), manufactured by the Motor Enterprise (EMO). It is a naturally aspirated inline 4-cylinder engine. Maximum engine power is 49 kW obtained at maximum speed rotation of 2300 rpm. Air cooling is a critical aspect of engine performance, and studying it experimentally can provide valuable insights into the engine's thermal behaviour and efficiency. One of the most problematic places is the high local temperature of the 4th cylinders sleeves. An innovative improvement of the cooling system is proposed. It is based on increasing the cooling air flow. It consists in the installation of new driving pulleys of the blowing turbine with different diameters. The use of these new pulleys allowed moderating the wall temperature of the liner and the cylinder head of the 4th cylinder and the thermal rebalancing of the engine. Significant improvements have been noted in cylinder wall temperature, exhaust gas temperature, and lubricating oil temperature. Drawing up the heat balance enabled us to quantify the useful work, the heat lost in the cooling water, the heat lost through the exhaust gases, the heat carried away by the lubricating oil and other losses (losses not accounted for). It is clear from the results that the high temperature in the engine has indeed been reduced and the cooling performance of the whole engine has been improved. The results show that the increase in airflow produced an improvement in cooling conditions as well as a reduction in exhaust gas temperatures which will have a significant impact on reducing NOx emissions. In future work, it is planned to improve the cooling system of the Emo F4L912 engine, by studying the effects of the geometry, number, and inclination of the turbine blades on the air flow supplied.

The rapidly growing consumption of petroleum-based fuels causes the government to expend a significant source of foreign currency on oil imports, which impacts the trade deficit in the government's current account. The purpose of the feasibility is to see how unleaded fuel blends impact the performance of an unmodified engine operating on numerous blends. This testing was performed using a four-stroke, single-cylinder, water-cooled multi-fuel engine (Computer controlled variable compression ratio multi-fuel injection, kirloskar type engine) with a carburetor fuel injection system. Multiple parameters such as brake thermal efficiency, brake power, engine torque, brake mean effective pressure, and brake specific fuel consumption were assessed throughout the benchmarks.Regular unleaded blends with multiple fuel proportions have been used in these investigations. Six ethanol blend fuels were tested and their physical and chemical characteristics were analyzed, with 90 octane numbers...

The large amount of heat is scattered in the internal combustion engine through exhaust gas, coolant, convective and radiant heat transfer. Of all these residual heat sources, exhaust gases have the potential to recover using various modern heat recovery techniques. Waste heat recovery from an engine could directly reduce fuel consumption, increase available electrical power and improve overall system efficiency and if it would be used a turbochargers that can also produce energy. This solution is called turbo aggregation and has other ways to develop it in other areas of research like the electrical field.

Este trabajo presenta una breve revisión a los conceptos
de la combustión aplicada a sistemas de propulsión por
reacción en la aeronáutica, además de mostrar y explicar
las ecuaciones que rigen estos fenómenos y su relación de
la mecánica, se da un breve paseo por la historia en la
evolución de los sistemas de propulsión y muestra las
distintas tecnologías desarrolladas y en proceso de
desarrollo en el ámbito de la combustión y su aplicación a
los motores a reacción, explica la diferencia de
configuración entre los motores a reacción civiles y
militares y su correspondencia a la relación de derivación

This work concerned experimental studies of heat transfer in a light-duty diesel engine. Combustion is affected by several parameters, such as pressure, engine speed, mass of injected fuel and in-cylinder gas flow. These parameters are in turn affected by the combustion chamber geometry and fuel spray characteristics. At high load the exhaust heat was increased more than at high engine speed. Swirl was found to speed up the combustion event and increased heat loss to the piston cooling, but had no measurable effect on exhaust heat loss. Exhaust gas recirculation (EGR) diverts part of the exhaust gas and mixes it with intake air. The recirculated gas acts as a heat sink and reduces incylinder temperatures and thus, heat losses. The air-fuel ratio is another important factor. More air resulted in faster combustion while also increasing exhaust gas temperature. Altering the combustion chamber geometry affected both in-cylinder gas flow and mixing. A more open and shallow design was found to redistribute heat losses from cooling media to exhaust. The original injectors were proven to have a higher fuel flow than the two other configurations, but faster combustion and less heat in the exhaust was mainly found with the injectors with fewest holes. Hot exhaust gases could be more useful than hot cooling media, because that heat may be extracted and used to improve engine efficiency. This reduces fuel consumption, and consequently emissions of greenhouse gases, which contribute to global warming. The world energy demand is still increasing, and more natural resources are being used. Higher efficiency requires less fuel, and thereby reduces the impact on environment and humanity. The work was performed in a 4-cylinder light-duty diesel engine. Temperatures and mass flow measurements were performed in cooling media and exhaust gas. From these calculations were executed to find out the heat fractions emitted to each medium. Two combustion chamber geometries and three injectors were tested and compared with respect to their impact on combustion and heat losses.

This work concerned experimental studies of heat transfer in a light-duty diesel engine. Combustion is affected by several parameters, such as pressure, engine speed, mass of injected fuel and in-cylinder gas flow. These parameters are in turn affected by the combustion chamber geometry and fuel spray characteristics. At high load the exhaust heat was increased more than at high engine speed. Swirl was found to speed up the combustion event and increased heat loss to the piston cooling, but had no measurable effect on exhaust heat loss. Exhaust gas recirculation (EGR) diverts part of the exhaust gas and mixes it with intake air. The recirculated gas acts as a heat sink and reduces in-cylinder temperatures and thus, heat losses. The air-fuel ratio is another important factor. More air resulted in faster combustion while also increasing exhaust gas temperature. Altering the combustion chamber geometry affected both in-cylinder gas flow and mixing. A more open and shallow design was fo...

A “Nitro-Vacuum Engine” comprises of a nitrogen cylinder, an engine block and a vacuum pump. Pressurized nitrogen gas is used to drive the piston and vacuum pump is installed to assist the piston movement. In this paper, construction and working details of “Nitro-Vacuum Engine” are explained. Also, pressure of the nitrogen gas required to drive the piston and minimum time in which vacuum pump can evacuate the gas are calculated, along with the power produced by the engine and it’s comparison with modern conventional engines. The purpose of this engine is to eliminate the concept of combustion from engines and move towards a green and clean environment.

The paper deals with the integration between a kinematic Stirling engine and a fluidized bed combustor for micro-scale cogeneration of renewable energy. A pilot-scale facility integrating a 40 kW t combustor and a γ-type Stirling engine (0.5 kW e ) was set up and tested to demonstrate the feasibility of this solution.

A thermodynamic analysis of a naturally aspirated, four-stroke, diesel engine, with a precombustion chamber under firing conditions is presented. Special attention is given in setting-up theequations expressing the work, flow and heat transfer processes during the open and closed part of the cycle, as well as the combustion processes in the two chambers, taking into account their interaction. For the calculation of the heat transfer in both main chamber and prechamber, a turbulence model is proposed. Inside the throat connecting the two chambers, heat exchange takes place between gas and walls. A modification extension of the combustion model of Whitehouse and Way is used for the divided combustion chamber. An experimental investigation is conducted on a diesel engine of this type. The experimental results concerning the performance of the engine are found to be in good agreement with the theoretical results obtained from the computer program implementing the analysis.

Principle of charge air cooling of the internal combustion engine with an aerothermopressor is proposed. It is implemented on the transport ship regular line. Arising thermogasdynamic compression allows increasing the air pressure. The aerothermopressor application in the charge air cooling systems makes it possible to reduce the power consumed by compressors, Nc by 3-10%, thereby the engine power is increased by 1-3% and the specific fuel consumption is decreased by 2-4%. It is established that in case of increasing the ambient air temperature tamb at the turbocharger input the effect from the aerothermopressor used for cooling of the charge air is increased: the turbocharger power reduction DN C is increased with a corresponding increase in engine power and a decrease in specific fuel consumption. The relative (related to air flow) water mass flow is determined, which has to be injected at completely evaporated in a thermal overpressure: 0.02-0.05 (2-5%).

Acetone and other volatile solvents are often utilized in industrial applications. Acetone is mainly used for industrial cleaning when lab material is contaminated with undesired residue. After the acetone is used to clean lab equipment, often times companies discard the solvents at a large expense. This project focuses on creating a small scale acetone distillation system to purify these contaminated solvents in order to reuse them. This paper will outline the research, design , and assembly of this system. The group assembled the contaminated acetone distillation system and provided recommendations for improvements to the system that can create a more efficient and commercialized distillation unit.

A special type of the gas engine with external combustion is called Stirling engine. The mechanism has two pistons with two volumes inside. The pistons are connected together through cooler, regenerator and warmer. The engine effectivity depends on the piston movement behaviour. The usual sinusoidal time curve leads to low effectiveness. The quick movement from lower to upper position with a certain delay in both top and bottom dead centres is more effective. The paper deals with three types of mechanisms, analyzing the piston movement, and their behavior. Special emphasize is taken to the piston movement regime.

The study of heat transfer phenomena in diesel engines is a very complex task considering the number of engine components such as intake and exhaust manifolds, lubricant oil and coolant subsystems, the different heat transfer mechanisms (conduction, convection, and radiation). This paper presents simulation results using a dual-zone model associated to GT-Suite simulation software for the calculation of convective heat transfer from gas to the cylinder wall, radiation heat transfer, gas pressure and temperature for low, partial and full load engine as a function of crank angle for a single-cylinder diesel engine. In this present article, a numerical simulation model was created to foresee the main combustion characteristics, and the simulated results were approved through the reference experiment data. Simulation results showed that any increase in the mass of fuel injected into the combustion chamber would generate a significant increase in the level of pressure and temperature of ...

To meet the needs of forward deployed soldiers and disaster relief personnel, a mobile water distillation system was designed and tested. This system uses waste engine heat from the exhaust flow of an internal combustion engine to vaporize water for the purpose of removing impurities. The vapor is condensed back down to water in a finned condenser that experiences forced convection. The system pumps heat transfer oil through a 0.61 meter long, cross flow, annulus-type heat exchanger installed over a section of exhaust pipe where the oil experiences a AT of 7°C. The hot heat transfer oil is then piped to a boiler where it releases its heat to the water and returns to the exhaust heat exchanger to be reheated. Testing demonstrated that the system has a heat up time of 30 minutes, and a steady state distillation rate of 2 gallons per hour. In steady state, the system removes and transfers heat from the exhaust at a rate of 4600 Watts.

The object of research is the air-cooling system, for F4L912 direct injection diesel engine (mounted on the bench), manufactured by the Motor Enterprise (EMO). It is a naturally aspirated inline 4-cylinder engine. Maximum engine power is 49 kW obtained at maximum speed rotation of 2300 rpm. Air cooling is a critical aspect of engine performance, and studying it experimentally can provide valuable insights into the engine's thermal behaviour and efficiency. One of the most problematic places is the high local temperature of the 4th cylinders sleeves. An innovative improvement of the cooling system is proposed. It is based on increasing the cooling air flow. It consists in the installation of new driving pulleys of the blowing turbine with different diameters. The use of these new pulleys allowed moderating the wall temperature of the liner and the cylinder head of the 4th cylinder and the thermal rebalancing of the engine. Significant improvements have been noted in cylinder wall temperature, exhaust gas temperature, and lubricating oil temperature. Drawing up the heat balance enabled us to quantify the useful work, the heat lost in the cooling water, the heat lost through the exhaust gases, the heat carried away by the lubricating oil and other losses (losses not accounted for). It is clear from the results that the high temperature in the engine has indeed been reduced and the cooling performance of the whole engine has been improved. The results show that the increase in airflow produced an improvement in cooling conditions as well as a reduction in exhaust gas temperatures which will have a significant impact on reducing NOx emissions. In future work, it is planned to improve the cooling system of the Emo F4L912 engine, by studying the effects of the geometry, number, and inclination of the turbine blades on the air flow supplied.

This paper investigates characterization of a small custom-built double-acting gamma-type stirling engine. Stirling-cycle engine is a reciprocating energy conversion machine with working spaces operating under conditions of oscillating pressure and flow. These conditions may be due to compressibility as wells as pressure and temperature fluctuations. In standard literature, research indicates that there is lack of basic physics to account for the transport phenomena that manifest themselves in the working spaces of reciprocating engines. Previous techniques involve governing equations: mass, momentum and energy. Some authors use engineering thermodynamics. None of these approaches addresses this particular engine. A technique for observing and analyzing the behavior of this engine via parametric spectral profiles has been developed, using laser beams. These profiles enabled the generation of pv-curves and other trajectories for investigating the thermos-physical and thermos-hydrodynamic phenomena that manifest in the exchangers. The engine's performance was examined. The results indicate that with current load of 35.78A, electric power of 0.505 kW was generated at a speed of 240 rpm and 29.50 percent efficiency was obtained.

The need to reduce the impact of energy on the environment requires the development of decarbonized systems that do not use carbon, as well as the determination of optimal parameters for their operation. The purpose of the work is to establish the features of the organization of the working process of the combustion chamber of a gas turbine engine that operates on gaseous ammonia. The thermodynamic and gas dynamic processes in a hybrid gas turbine combustion chamber with partial mixing of components outside the combustion zone were chosen as the object of study. To predict the aerodynamic structure of chemically reacting flows in the ammonia-burning combustion chamber, a three-dimensional modeling method was used. The proposed mathematical model is based on the equations of continuity, conservation of momentum, conservation of energy, transport of chemical components of the mixture, as well as equations that describe the characteristics of the turbulence of swirled flows. The Eddy-Dissipation-Concept (EDC) combustion model was used to calculate the oxidation processes of ammonia in the gas turbine engine combustion chamber, which takes into consideration the interaction of kinetics and turbulence. To calculate the kinetic aspects of high-temperature ammonia combustion in air, a chemical scheme with 71 reactions and 22 components is proposed, which can be used over a wide range of temperatures, pressures, and excess air coefficients. A designed scheme of a combustion chamber operating on gaseous ammonia is proposed. The features of the organization of the working process in the combustion chamber with partial mixing of components outside the combustion zone at a thermal power of 1.0 MW are considered. Three-dimensional CFD calculations of energy and emission characteristics of the ammonia-burning combustion chamber are carried out. The possibility of complete ammonia combustion in the volume of the fuel-burning device with effective swirling of primary air is demonstrated. The results obtained can be used in the development of combustion chambers of gas turbine engines for decarbonized energy systems, including fuel cells.

In this study, mathematical models of a novel mechanism, rhombic-drive, for a two-stroke, spark ignition (SI) engine, and a two-stroke SI engine with a conventional slider-crank mechanism were performed in MATLAB software. Their performances were compared with kinematic and thermodynamic analyses. Mathematical model was conducted according to real cycle approach and some of the operating parameters such as compression ratio, swept volume, heat release time, and lambda were kept identical for both engines. Pressure, volume, temperature, heat release, heat transfer coefficient, work, piston speed, and acceleration changes were examined. Maximum in-cylinder pressure was taken at 222°CA with 4,188 kPa for rhombic-drive engine while 190°CA with 4,003 kPa for slider-crank mechanism engine and maximum temperature was only 39 K higher for rhombicdrive mechanism engine. Theoretical thermal efficiencies of rhombic-drive and slider-crank mechanism were 31.14% and 31.87%, respectively. Effective power of rhombic-drive mechanism engine was 2.12 kW, whereas slider-crank mechanism engine was 2.17 kW. Mechanical efficiency of rhombic-drive engine was obtained 85.89%, while this was only 86.21% for slider-crank mechanism engine.

To support an arrest, a ship with good motion and good cooling is needed. The engine motion of the ship and the coolant of the boat engine are mutually sustainable so this is what allows the engine performance to work optimally. The main engine of the ship if there is no cooler has constrained problem that is wear and tear on the main engine and even worse can damage the engine so it nees a tool to absorb heat from theengine that is the heat exchanger.

The need to reduce the impact of energy on the environment requires the development of decarbonized systems that do not use carbon, as well as the determination of optimal parameters for their operation. The purpose of the work is to establish the features of the organization of the working process of the combustion chamber of a gas turbine engine that operates on gaseous ammonia. The thermodynamic and gas dynamic processes in a hybrid gas turbine combustion chamber with partial mixing of components outside the combustion zone were chosen as the object of study. To predict the aerodynamic structure of chemically reacting flows in the ammonia-burning combustion chamber, a three-dimensional modeling method was used. The proposed mathematical model is based on the equations of continuity, conservation of momentum, conservation of energy, transport of chemical components of the mixture, as well as equations that describe the characteristics of the turbulence of swirled flows. The Eddy-Dissipation-Concept (EDC) combustion model was used to calculate the oxidation processes of ammonia in the gas turbine engine combustion chamber, which takes into consideration the interaction of kinetics and turbulence. To calculate the kinetic aspects of high-temperature ammonia combustion in air, a chemical scheme with 71 reactions and 22 components is proposed, which can be used over a wide range of temperatures, pressures, and excess air coefficients. A designed scheme of a combustion chamber operating on gaseous ammonia is proposed. The features of the organization of the working process in the combustion chamber with partial mixing of components outside the combustion zone at a thermal power of 1.0 MW are considered. Three-dimensional CFD calculations of energy and emission characteristics of the ammonia-burning combustion chamber are carried out. The possibility of complete ammonia combustion in the volume of the fuel-burning device with effective swirling of primary air is demonstrated. The results obtained can be used in the development of combustion chambers of gas turbine engines for decarbonized energy systems, including fuel cells.

For this article, experimental work was conducted to integrate a Stirling cycle unit onto a vehicle radiator for enhancing the cooling system of a car engine. The Stirling cycle was integrated with the car engine to act as a pressure relief valve for the radiator. The performance of the radiator was improved by increasing the rate of heat transfer from the radiator and the Stirling cycle unit. Experimental results showed that using the Stirling cycle had improved the heat transfer from the radiator by removing heat from the water circulated in the engine, which caused a reduction of temperature up to 15°C in the coolant inlet temperature entering the combustion engine. This reduction in the coolant temperature was also dependent on the coolant mass flow rate. The coolant inlet temperature and pressure of the combustion engine are compared with those obtained with and without using the Stirling cycle.

Thrust regulation is applied to maintain the performance of the liquid propellant rocket engine. The thrust level of a rocket engine can be readily controlled by adjusting the number of propellants introduced into the combustion chamber. In this study, a gas generator design is proposed in which thrust regulation is maintained by performing secondary combustion in the divergent section of the nozzle of a gas generator. Tangential and normal injection techniques have also been studied for better combustion analyses. A normal injection technique is used for the experiment and CFD results are validated with the experimental data. Chemical equilibrium analyses are also performed by minimizing Gibbs free energy with the steepest descent method augmented by the Nelder–Mead algorithm. These equilibrium calculations give the combustion species as obtained through the CFD results. Performance evaluation of the rocket engine, with and without secondary combustion in the gas generator, led to ...

An experimental investigation and a burning-rate analysis have been performed on a production 1.4 liter compressed natural gas (CNG) engine fueled with methane-hydrogen blends. The engine features a pent-roof combustion chamber, four valves per cylinder, and a centrally located sparkplug. The experimental tests have been carried out in order to quantify the cycle-to-cycle and the cylinder-to-cylinder combustion variation. Therefore, the engine has been equipped with four dedicated piezoelectric pressure transducers placed on each cylinder and located by the spark plug. At each test point, in-cylinder pressure, fuel consumption, induced air mass flow rate, pressure, and temperature at different locations on the engine intake and exhaust systems as well as "engine-out" pollutant emissions have been measured. The signals related to engine operation have been acquired by means of a National Instruments PXI-DAQ system and software developed in house. The acquired data have then been processed through a combustion diagnostic tool resulting from the integration of an original multizone thermodynamic model with a computer-aided design (CAD) procedure for the evaluation of the burned-gas front geometiy. The diagnostic tool allows the burning velocities to be computed. The tests have been performed over a wide range of engine speeds, loads, and relative air-fuel ratios (up to the lean operation limit (WL)). For stoichiometric operation, the addition of hydrogen to CNG has produced a brake-specific fuel combustion (bsfc) reduction ranging between 2% and 7% and a brake-specific total unburned hydrocarbons (bsTHCs) decrease up to 40%. These benefits have appeared to be even higher for lean mixtures. Hydrogen has shown to significantly enhance the combustion process, thus leading to a sensibly lower cycle-to-cycle variability. Hydrogen addition has generally resulted in extended operation up to relative air-to-fuel ratio (RAFR) = J.8. Still, the LOL consistently varies depending on the considered cylinder.

The need to reduce the impact of energetics on the environment determines the need to develop and adapt energy-efficient decarbonized systems, as well as determine the ranges of their rational parameters. The aim of the work is to study the energy and emission characteristics of gaseous ammonia burning in the combustion chamber of a gas turbine engine with over-expansion. The combustion chamber for the afterburning of waste gases of a hightemperature fuel cell as part of a gas turbine unit with over-expansion was chosen as the object of the investigation. For detailed forecasting of the characteristics of the combustion chamber operating on ammonia, an approach was used, according to which the burning device is considered as a set of different chemical reactors (perfectly stirred, plug-flow), simulating the main processes of chemical transformations in different sections of the flame tube of the combustion chamber. A reactor model of the combustion chamber operating on gaseous ammonia has been developed, in which the relevant reactors simulate the primary zone of the combustion chamber, the dilution zone and the processes of mixing of secondary air, which is supplied to the respective zones, with the main flow. The mathematical model is based on the equations of conservation of mass and energy for a chemically reacting system. As a kinetic scheme of gaseous fuel burning in the combustion chambers of gas turbine engines, the mechanism of high-temperature oxidation of ammonia is used, taking into consideration the chemical reactions of hydrogen combustion, which includes 71 reactions with 22 components. The influence of operational parameters of the combustion chamber on the distribution of temperature and concentrations of chemically reactive components in the volume of the burning device is considered. Calculations of the working process of the combustion chamber were carried out for a thermal power of 1.,0 MW, a pressure of 0.3 MPa and at variation of the excess air coefficient from 1.41 to 2.03. The possibility of stable operation of the combustion chamber on ammonia under the conditions of effective swirling of the primary air is shown. At the same time, the residence time of the reagents in the primary combustion zone should exceed 0.025 seconds, which is possible if there are powerful devices for stabilizing combustion. The results of the work can be used in the development of combustion chambers of gas turbine engines for decarbonized energy systems, as well as for afterburning products of solid oxide fuel cells operating as part of hybrid power plants.

Recently, precise analysis of energy flow in engines has become necessary to improve fuel economy. An integrated engine thermal management model, which is introduced in this paper, is suitable for that process. The model consists of six sub-models for thermal mass, coolant, lubricant, heat transfer, friction, and exhaust. The sub-models are coupled to each other and they exchange heat and signals. Combustion energy flow analysis and temperature estimation of the engine components and working fluids were simulated under various conditions. Simulation results were compared with experimental data and they showed good agreement. Then, a variable-speed water pump (VSWP) to control coolant flow was applied in place of a conventional water pump. Engine warm-up time decreased with proper coolant flow control, and fuel economy could be improved by 2.5%.

Mostly   in all automobiles   reciprocating I.C. engines are used in spite of having some lacunas i.e. incomplete combustion of fuel, due to which lower thermal efficiency obtained. It having more nos. of moving parts due to which balancing of engine becomes a tedicious task. Also weight to power ratio of engine becomes excessively high. This paper describes a new concept of rotary vane type engine. An alternative approach to reciprocating engine. In this article author has chosen stator, rotor and different vanes i.e. 4, 6, & 8 for optimizing compression ratio, cubic capacity and brake horse power at 6000 rpm.

The floor heating system with phase change materials (PCMs) for thermal storage is an effective approach to increase the floor thermal capacity and reduce indoor temperature fluctuation range. A two-dimensional numerical model of the floor heating system combined with PCM was developed to investigate its dynamic thermal performance in winter. To verify the reliability of the model, an experimental room was established in Beijing, China. The experiment results agreed well with the modelling results, which demonstrated that the numerical model was reliable. The effects of the phase change temperature, latent heat and thermal conductivity of PCM on the thermal performance of the floor were numerically investigated. The results showed that the phase change temperature and thermal conductivity of PCM had a significant influence on thermal comfort. At the same time, these two thermal physical parameters also played a critical role in improving the utilization rate of PCM. Conversely, the latent heat, in the range of 100 to 200 kJ/kg, had no obvious influence on the thermal performance of the floor. PCM with phase change temperature of 313 K was recommended, which could increase the average indoor temperature by 2.2 K, increase the thermal energy storage ratio by 12% and reduce indoor temperature fluctuation range by 2.2 K.

The study of heat transfer phenomena in diesel engines is a very complex task considering the number of engine components such as intake and exhaust manifolds, lubricant oil and coolant subsystems, the different heat transfer mechanisms (conduction, convection, and radiation). This paper presents simulation results using a dual-zone model associated to GT-Suite simulation software for the calculation of convective heat transfer from gas to the cylinder wall, radiation heat transfer, gas pressure and temperature for low, partial and full load engine as a function of crank angle for a single-cylinder diesel engine. In this present article, a numerical simulation model was created to foresee the main combustion characteristics, and the simulated results were approved through the reference experiment data. Simulation results showed that any increase in the mass of fuel injected into the combustion chamber would generate a significant increase in the level of pressure and temperature of ...

The purpose of carrying out present work is to design, build and test a rhombic drive Stirling engine with a β-type configuration consisting of two dynamic pistons (displacer and power) reciprocates in the in-line concentric cylinder arrangement. The displacement rod is assembled concentrically inside the power piston rod. The rhombic drive mechanism is proposed in such a way that, by using a pair of gear wheels the sliding motion of both piston rods is controlled and thus, an engine is balanced. The developed prototype has a swept volume of 75 cm 3 with the displacer piston and power piston cylinder hot ends heated by liquefied petroleum gas (LPG) burner and cooled water, respectively. It uses air as the working gas at atmospheric pressure for initial charging of the engine. Several designs were studied before settling on a β-type configuration. The LPG gas burner was considered as a potential heat source. The various elements of an engine (heater, cooler, re-generator, flywheel and piping systems) were designed, constructed and analyzed. The testing results revealed that the engine at initial atmospheric air filling started working in only about 120 seconds at an LPG heater temperature of 400˚C (824˚F) with 280 rpm. At a heater temperature of 550˚C (1022˚F), the engine speed was 630 rpm. At the engine speed of 245 rpm, the maximum torque was 0.215 Nm, while the maximum power was 8 Watts at 355 rpm. Engine speed increased with the increase of flame temperature. Several tests were performed on the engine to improve its running efficiency and critical problem areas were isolated and addressed. Moreover, results revealed that Stirling engines working with relatively low-temperature air are potentially attractive engines of the future, especially LPG powered low temperature differential Stirling engines. The Stirling engine was capable of generating between 50 to 100 Watts of electricity.

The purpose of carrying out present work is to design, build and test a rhombic drive Stirling engine with a β-type configuration consisting of two dynamic pistons (displacer and power) reciprocates in the in-line concentric cylinder arrangement. The displacement rod is assembled concentrically inside the power piston rod. The rhombic drive mechanism is proposed in such a way that, by using a pair of gear wheels the sliding motion of both piston rods is controlled and thus, an engine is balanced. The developed prototype has a swept volume of 75 cm 3 with the displacer piston and power piston cylinder hot ends heated by liquefied petroleum gas (LPG) burner and cooled water, respectively. It uses air as the working gas at atmospheric pressure for initial charging of the engine. Several designs were studied before settling on a β-type configuration. The LPG gas burner was considered as a potential heat source. The various elements of an engine (heater, cooler, re-generator, flywheel and piping systems) were designed, constructed and analyzed. The testing results revealed that the engine at initial atmospheric air filling started working in only about 120 seconds at an LPG heater temperature of 400˚C (824˚F) with 280 rpm. At a heater temperature of 550˚C (1022˚F), the engine speed was 630 rpm. At the engine speed of 245 rpm, the maximum torque was 0.215 Nm, while the maximum power was 8 Watts at 355 rpm. Engine speed increased with the increase of flame temperature. Several tests were performed on the engine to improve its running efficiency and critical problem areas were isolated and addressed. Moreover, results revealed that Stirling engines working with relatively low-temperature air are potentially attractive engines of the future, especially LPG powered low temperature differential Stirling engines. The Stirling engine was capable of generating between 50 to 100 Watts of electricity.

The study of heat transfer phenomena in diesel engines is a very complex task considering the number of engine components such as intake and exhaust manifolds, lubricant oil and coolant subsystems, the different heat transfer mechanisms (conduction, convection, and radiation). This paper presents simulation results using a dual-zone model associated to GT-Suite simulation software for the calculation of convective heat transfer from gas to the cylinder wall, radiation heat transfer, gas pressure and temperature for low, partial and full load engine as a function of crank angle for a single-cylinder diesel engine. In this present article, a numerical simulation model was created to foresee the main combustion characteristics, and the simulated results were approved through the reference experiment data. Simulation results showed that any increase in the mass of fuel injected into the combustion chamber would generate a significant increase in the level of pressure and temperature of ...

In this paper, a new micromachined reciprocating engine utilizing the pressure built up by combustion has been designed and fabricated. As a basework for development of micromachined engines, initial combustion experiments have been performed using a microscale combustor made by conventional machining. From these experiments, a new micromachined engine has been proposed and its proper chamber dimension has been determined for stable ignition and flame propagation. The proposed engine has a unique structure simplified from the general reciprocating engines in order to make it suitable to be fabricated using MEMS processes and applied for movable microsystems. We have demonstrated actual one-shot combustion test of the fabricated prototype microengine and generation of a movable power using premixed hydrogen and air fuel.

Stirling engines, unlike internal combustion engines, are engines that generate power by using any type of heat energy source. In these engines, air, helium, and hydrogen are generally preferred as the working fluid. In terms of environment, Stirling engines have lower NO x, HC, and CO emission. The drive mechanisms vary according to the type of the engine. Suitable drive mechanisms need to be designed to obtain high power output from the engine. This study chronologically examines the efforts of development in Stirling engines. Stirling, Ericsson, and Carnot theoretical cycles are compared and their theoretical efficiency is show to be equal. It is shown that the thermodynamic properties of working fluids used in Stirling engines change according to the temperature. The effect of the working fluids on the engine's performance is discussed. The drive mechanisms used in Stirling engine throughout the historical development is studied in details. Theoretical and experimental studies performed on rhombic drive mechanisms that are distinguished among the drive mechanisms used in such engines by their advantages are examined. The rhombic drive mechanism is firstly used in Stirling engines by the Philips Company in 1953. After this date, the applications of the rhombic drive mechanism in various engines with different characteristics were assessed in terms of performance by companies and researchers. The comparison with other drive mechanisms shows that rhombic drive mechanism is the most suited drive mechanism for beta-type Stirling engines. century lowered the interest in Stirling engines. But in 1937, the development of Stirling engines resumed in Philips Research Laboratories in order to create small, quiet, economic, and practical electricity generators [9]. In later years, companies like General Motors Company (U.S.A.), DAF (Netherlands), United Stirling (Sweden), MAN-MWM Group (Germany), Ford Motors Company (U.S.A.), Siemens (Germany), Cummins (U.S.A.), and Perkins (U.K.), and NASA (U.S.A.) conducted large scale researches on Stirling engines. Today, the development process of Stirling engines is continuing in companies and universities in various countries. The aims are the reduction of the dead space, the minimization of manufacturing and maintenance costs, and the augmentation of thermal efficiencies of these engines that share the same working principle. Stirling engines, except for their manufacturing and maintenance costs, are low cost and environment friendly alternative power sources. Stirling engines that can work with various energy sources are used in many fields such as space technology, irrigation, refrigeration, and electricity generation [10,11]. This paper examines the historical development, the thermody

Mesin diesel adalah salah satu jenis motor bakar torak, yang pembakaran bahan bakarnya terjadi akibat adanya tekanan udara yang tinggi di dalam ruang bakar. Motor diesel proses pembakaran menghasilkan energi panas dan menaikkan tekanan yang tinggi di dalam silinder, tekanan tersebut untuk dirubah menjadi energi mekanik pada poros engkol. maka diperlukan sistem pendingin pada mesin induk. Sistem pendingin adalah  salah  satu sistem yang berfungsi menjaga temperatur mesin pada suhu tertentu sesuai dengan desain yang ditentukan agar mesin diesel dapat beroperasi secara berkelanjutan. Penelitian ini bertujuan untuk mengetahui cara kerja sistem pendingin kapal, untuk mengetahui cara perawatan sistem pendigin kapal, untuk mengetahui gangguan yang terjadi pada sistem pendingin dan melakukan perbaikan. Adapun cara kerja sistem pendingin di KM Sumber Fortuna menggunakan sistem pendingin secara tidak langsung / tertutup dengan menggunakan heat exchanger sebagai tempat media penukar bejana pan...

Space travel requires high-powered, efficient rocket propulsion systems for controllable launch vehicles and safe planetary entry. Interplanetary travel will rely on energy-dense propellants to produce thrust via combustion as the heat generation process to convert chemical to thermal energy. In propulsion devices, combustion can occur through deflagration or detonation, each having vastly different characteristics. Deflagration is subsonic burning at effectively constant pressure and is the main means of thermal energy generation in modern rockets. Alternatively, detonation is a supersonic combustion-driven shock offering several advantages. Detonations entail compact heat release zones at elevated local pressure and temperature. Specifically, rotating detonation rocket engines (RDREs) use detonation as the primary means of energy conversion, producing more useful available work compared to equivalent deflagration-based devices; detonation-based combustion is poised to radically im...

In the name of Allah that the most Gracious, the most Merciful" Foremost, my greatest gratitude goes to ALLAH SWT for giving me the energy, strength and spirit to make it possible to complete the thesis under the title of "Development and Performance Characterization of an Alpha V-Type Stirling Engine Converted Diesel Engine (SCDE)".

This paper presents the performance of an Alpha-type Stirling engine with and without a regenerator. The Alpha Stirling engine with a V-cylinder arrangement has two pistons that fit in hot and cold cylinders separately. The prototype engine has swept volume of 79 cm 3. Working gas is ambient air and coolant is water. The engine performance test was conducted in two operating modes as a heat pump and a heat engine. Working as a heat pump, temperature drop at the cold cylinder was measured relative to work input from an induction motor. By varying its speed using an inverter, the cooling curves of the engine with and without regenerative heat exchanger were obtained for comparison. Working as a heat engine, on the contrary, heat input instead of work input as in the heat pump was applied to the engine by a fuel burner at a constant feed rate of LPG. The temperature on the cold cylinder is controlled by cooling water from the cooler. By varying the cooling water temperature, the variations of work output were measured from the output shaft by the rope brake dynamometer. The performance results of the two operating modes with and without regenerator were compared.

For this article, experimental work was conducted to integrate a Stirling cycle unit onto a vehicle radiator for enhancing the cooling system of a car engine. The Stirling cycle was integrated with the car engine to act as a pressure relief valve for the radiator. The performance of the radiator was improved by increasing the rate of heat transfer from the radiator and the Stirling cycle unit. Experimental results showed that using the Stirling cycle had improved the heat transfer from the radiator by removing heat from the water circulated in the engine, which caused a reduction of temperature up to 15°C in the coolant inlet temperature entering the combustion engine. This reduction in the coolant temperature was also dependent on the coolant mass flow rate. The coolant inlet temperature and pressure of the combustion engine are compared with those obtained with and without using the Stirling cycle.

Heat engine converts chemical engine available in fuel to useful mechanical energy. One of the most famous heat engines is internal combustion (IC) engine. IC engine plays a pivotal role in transportation and other industrial applications. A lot of waste heat is rejected from a typical IC engine as the conversion efficiency of this type of engine is only about 35-40 %. The waste heat has the potential to be tapped and converted into useful energy. This can help to increase the performance of the IC engine system. This work focused on the conversion of the waste heat energy of the IC engine into electricity by using thermoelectric generator (TEG). The aim of the project was to demonstrate the applicability of TEG to convert waste heat from exhaust to useful electrical energy. Two TEGs were individually tested to attain the electrical characterization and also tested on series and parallel connections. The study showed that the series connection of TEGs has improved and increased volt...

In concentrated solar energy applications, the Stirling engine is the optimum option for extracting mechanical work. The engine's most notable features are minimal noise, vibration, and pollution, as well as its capacity to function with any external heat source, including biomass, solar energy, and industrial waste. The gamma-type STE-1008 Stirling engine is the subject of our research. This engine can handle a maximum charging pressure of 10 bar. The engine is divided into two sections (expansion and compression) and three heat exchangers (regenerator, cooler, and heater). The cooler is a finned aluminium heat exchanger with 144 internal fins, each with a cross-sectional area of 1 mm by 10 mm. The regenerator is fitted with a diameter of 31 m and a volumetric porosity of 90%. This investigation employed a random fiber with three different metals: stainless steel, copper, and aluminium. Nitrogen and air served as the working fluids. From the results, stainless steel, copper, an...

The free piston Stirling engine external combustion system was simulated to investigate the diesel-air combustion characteristics in order to demonstrate its feasibility by computational fluid dynamics (CFD). The different effects on combustion were distinguished by analyzing the combustion burner, the injection position of diesel oil, the front tube arrangement of Stirling heater head and the back fin. The results show that the tilted front tube arrangement of the heater head with the back fin is the best practicable technology while the distance between the diesel nozzle position and the swirler top is 0. Its total heat flux is 15.6 kW, and the average heat transfer coefficients of the front and back tubes are 127 W/(m 2 • K) and 192 W/(m 2 • K), respectively. The heat transfer is mainly through convection, and the proportion of radiative heat transfer is only 16.9%. The best combustion efficiency of the free piston Stirling engine external combustion system is 86%.

Konservasi energi menjadi hal yang diperhitungkan di masa depan. Cara efektif mengurangi permintaan energi  adalah menggunakan energi lebih efektif . Penukar kalor merupakan cara mentransfer energi yang banyak  digunakan untuk oil refinery, industri kimia dan makanan. Salah satu aplikasi alat penukar kalor adalah heat  exchanger yang merupakan perangkat penyedia energi termal antara dua atau lebih cairan pada suhu berbeda.  Salah satu jenis heat exchanger yang sering digunakan heat exchanger shell and tube Tujuan dari studi literatur  ini untuk mengetahui besar koefisien perpindahan panas dan mendapatkan nilai U. Pada setiap literatur  membandingkan setiap jurnal dan mereview jurnal yang diperoleh. Dari setiap jurnal didapatkan nilai U  dengan memvariasi variable bahan coolant, pengaruh konsentrasi coolant, laju alir fluida dan suhu fluida. Dari  hasil pembahasan penggunaan nanofluida menambah koefisien perpindahan panas sebesar 15% daripada  menggunakan fluida air. Pengaturan suhu ...

The Stirling engine is a simple type of external-combustion engine with an external combustion engine based on cyclic compression and expansion of gas at different temperature levels. It has high efficiency; low vibration levels, simple structure and can run on any combustible fuels. It has been the object of numerous studies. This paper presents an analysis of a Stirling engine model GENOA 03 for electric power generation, of 3 KW of nominal power with pressurized air as working fluid, currently under development. To improve its performance and ensure a good operational reliability, it is necessary to carry out a modelling of the engine in all its operating range. This requires complex numerical models that simulate the behaviour of any element of the engine in a cycle. Two typologies of thermodynamic models are developed in this work: isothermal and adiabatic. The main benefits and shortcomings of each model are mentioned. The geometry and conditions of the engine have been adapte...

Thrust regulation is applied to maintain the performance of the liquid propellant rocket engine. The thrust level of a rocket engine can be readily controlled by adjusting the number of propellants introduced into the combustion chamber. In this study, a gas generator design is proposed in which thrust regulation is maintained by performing secondary combustion in the divergent section of the nozzle of a gas generator. Tangential and normal injection techniques have also been studied for better combustion analyses. A normal injection technique is used for the experiment and CFD results are validated with the experimental data. Chemical equilibrium analyses are also performed by minimizing Gibbs free energy with the steepest descent method augmented by the Nelder–Mead algorithm. These equilibrium calculations give the combustion species as obtained through the CFD results. Performance evaluation of the rocket engine, with and without secondary combustion in the gas generator, led to ...