Papers by Norhazwani Abd Malek
Low-dimensional nanomaterials for nanofluids: a review of heat transfer enhancement
Journal of Thermal Analysis and Calorimetry
Jurnal Teknologi, 2015
Computational Fluid Dynamics analysis on First Stage Nozzle in full scale multi-stage power stati... more Computational Fluid Dynamics analysis on First Stage Nozzle in full scale multi-stage power station gas turbine has been carried out. The main aim is to investigate the turbine thermal performance when cooling rate decreases at certain level. All calculations were executed using commercial CFD code, ANSYS FLUENT which is able to accurately predict the flow and conjugate heat transfer problem as demonstrated in this investigation. The modelling of gas turbine nozzle is assisted by geometric cloud data obtained from 3D scan. Preliminary calculation shows that at the given worst case scenario for, the maximum thermal stress experienced by the component is within the maximum yield strength of the nozzle material. However, the safety margin between the predicted stress and maximum allowable stress is very small.
Quantifying Energy Savings from Implementation of Energy Conservation Measures (ECMs) in a Residential Building: A Case Study of a Double Storey Bungalow in Malaysia
Journal of Energy and Environment, Dec 31, 2020
Jurnal Teknologi, 2015
This study is mainly to investigate the unsteady flows due to supercritical heat addition in high... more This study is mainly to investigate the unsteady flows due to supercritical heat addition in high speed condensing steam in steam turbines. To achieve this, condensation flow characteristic is investigated on 2D converging-diverging nozzle. A Computational Fluid Dynamics (CFD) code (FLUENT package) that adopted the Eulerian-Eulerian approach for modeling wet steam flow, was used. The condensing flow is governed by the compressible Navier-Stokes equations in conjunction with a wet steam multiphase model. The turbulence model selected for this work is Spalart Allmaras model which is based on the Reynolds Averaged Navier Stoke (RANS) model available in FLUENT. Results are then compared with previous researchers that use different methods including user defined code and experiment. The importance of this research study is to determine the accuracy of the software and method used and to compare the results with other researchers.The current work shows good agreement with the experimental...
International Journal of Engineering & Technology, 2018
This paper presents the design and development of a mini portable cooler that utilizes the Peltie... more This paper presents the design and development of a mini portable cooler that utilizes the Peltier effect to cool the human expressed breast milk (EBM) within 24 hours at the temperature range between 4°C-15°C to maintain the high quality of the EBM for use at a later date and the health of the baby who consume it. It is developed to overcome the tediousness of using cooler bag/box, which requires ice packs that need repetitive freezing. A few prototypes with different sizes and body materials, namely polystyrene, polypropylene and aluminium, were successfully developed and tested to get the minimum temperature using 5V power supply. In all graphs, the temperature is decreasing with time. The smallest size of the cooled space (18cm of width, 12cm of length and 14cm of height) has the lowest temperature compared to the other sizes for each body material. However, the lowest temperature of all body materials is obtained from aluminium with 11.2°C at 100 minutes. It also reaches below ...
Numerical Modelling of Dry and Wet Steam Flows in Converging-Diverging Nozzles
The Malaysia-Japan Model on Technology Partnership, 2014
Problem of water erosion in low pressure steam turbine stage is serious due to the formation of w... more Problem of water erosion in low pressure steam turbine stage is serious due to the formation of water droplets which travel at supersonic speed within the blade channel. The impact of these droplets could cause damage to turbine blade, and effort to understand the underlying mechanism of this type of flow has been devoted many years ago. This chapter describes the modelling of dry superheated and wet steam flows in two converging-diverging nozzles. The modelling is carried out using both in-house developed and commercial CFD code FLUENT. In this work, emphasis is given on understanding the capability of commercial CFD code to accurately predict the behaviour of dry and wet steam flow through the nozzles. The pressure and Mach number prediction using the commercial as well as in-house code show good agreement with one-dimensional analytical solution and experimental data. Quantitatively, further refinement to the geometrical mesh and mathematical model through user-defined function is desirable to increase the accuracy of the prediction using commercial CFD code.
One-dimensional analysis of the behaviour of wet steam at different inlet conditions
ABSTRACT The main aim of this paper is to estimate the likely behaviour of steam during an expans... more ABSTRACT The main aim of this paper is to estimate the likely behaviour of steam during an expansion process with the variation in the total inlet temperature. It is well-acknowledged that the position of limiting supersaturation was dependent on the steam conditions at inlet. Based on this hypothesis, an improved mathematical model is developed to observe the effect of changing the inlet total temperature to the flow properties. In the present work, a one-dimensional (1-D) time-marching compressible Euler solver that uses the second order cell-vertex finite volume spatial discretization and fourth orders Runge-Kutta temporal integration has been developed. Artificial viscosity is added by using Jameson's type 2nd and 4th. A single dimension is considered here as to demonstrate the main effects of spontaneous condensation without necessary complexity. The boundary conditions across the nozzle are imposed in the calculations. Based on the calculation, it is clear that the Mach number and pressure ratio is a good representation to the onset of condensation and are highly dependent on the total inlet temperature.
Mechanical Engineering, 2012
IOP Conference Series: Earth and Environmental Science, Jun 17, 2013
View the article online for updates and enhancements. Related content An experimental investigati... more View the article online for updates and enhancements. Related content An experimental investigation of pump as turbine for micro hydro application N Raman, I Hussein, K Palanisamy et al.-Disk brake design for cooling improvement using Computational Fluid Dynamics (CFD) Kannan M Munisamy and Ramel Shafik-Computational Fluid Dynamics (CFD) investigation onto passenger car disk brake design
Thermal comfort investigation on a naturally ventilated two- storey residential house in Malaysia
IOP Conference Series: Materials Science and Engineering, Sep 23, 2015
This paper presents a case study to investigate the human thermal comfort on a naturally ventilat... more This paper presents a case study to investigate the human thermal comfort on a naturally ventilated two-storey residential house in Malaysia. Three parameters were investigated in this study, namely the air temperature, air velocity and air humidity. These parameters were measured using the appropriate measuring device to obtain the actual data and compared with simulation results. The level of thermal comfort in the house was found to be poor as the parameters measured are over the limits specified by ASHRAE standards. Simulation on the model of the house was performed using the Computational Fluid Dynamics (CFD) commercial code, FLUENT to visualize the temperature distribution and air flow pattern and velocity in the house. The error between these two sets of data was acceptable and thus the simulation used in this study was validated. Comparison was also made in the CFD simulation to see the effects of using a ceiling fan installed in the house and without ceiling fan. The level of thermal comfort was poor in both cases as it did not satisfy the standards set by ASHRAE but more uniform temperature distribution inside the house was found when the ceiling fan was turned on. The thermal comfort level became critical in the afternoon as during this period, the house receives direct sunlight which causes the temperature inside the house to increase. Although the mechanical ventilation devices did not help to improve the thermal comfort in the house being studied, the CFD simulation results can be used by building designers to further improve the level of thermal comfort in naturally ventilated residential houses.
Jurnal Teknologi
This study is mainly to investigate the unsteady flows due to supercritical heat addition in high... more This study is mainly to investigate the unsteady flows due to supercritical heat addition in high speed condensing steam in steam turbines. To achieve this, condensation flow characteristic is investigated on 2D converging-diverging nozzle. A Computational Fluid Dynamics (CFD) code (FLUENT package) that adopted the Eulerian-Eulerian approach for modeling wet steam flow, was used. The condensing flow is governed by the compressible Navier-Stokes equations in conjunction with a wet steam multiphase model. The turbulence model selected for this work is Spalart Allmaras model which is based on the Reynolds Averaged Navier Stoke (RANS) model available in FLUENT. Results are then compared with previous researchers that use different methods including user defined code and experiment. The importance of this research study is to determine the accuracy of the software and method used and to compare the results with other researchers.The current work shows good agreement with the experimental...
This paper is the second of a set describing the implementation and economic analysis of an impro... more This paper is the second of a set describing the implementation and economic analysis of an improved solar photo voltaic (PV) system for Malaysian rural electrification. The work was carried out based on a case study in a rural community to replace their diesel-powered generators with the new renewable energy (RE) solutions, with buffer capacity for additional requirements. Based in the extensive tests done on the system, it is proven that the new improved design of solar power system can be implemented as it meets the technical requirements of the project.
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Papers by Norhazwani Abd Malek