Haslinda Mohamed Kamar
Universiti Teknologi Malaysia - UTM, Thermo Fluid, Faculty Member
- Thermodynamics, Automotive Air-conditioning, Thermal comfort, Indoor Air Quality, INDOOR AIR QUALITY, VENTILATION, ENERGY EFFICIENCY, CFD Analysis, and 14 moreThermo-fluid, Thermal Comfort Conditions in Malaysia, Fluid Mechanics, Energy efficiency, Computational Fluid Dynamics, Renewable Energy, Mechanical Engineering, Engineering, Energy, Energy and Environment, Wind Energy, Thermal Engineering, Thermo fluids, and Foundation Studiesedit
- Associate Professor, Department of Thermo-fluids, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Johor, Malaysiaedit
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The thrust to find new technology and materials has been greatly increasing due to environmental and technological challenges in the progressive world. Among new standard materials and advanced nano-materials that possess a huge potential... more
The thrust to find new technology and materials has been greatly increasing due to environmental and technological challenges in the progressive world. Among new standard materials and advanced nano-materials that possess a huge potential and superior thermal, mechanical, optical, and magnetic properties, which have made them excellent and suitable components for mechanical engineering applications. The current review paper deals with recent enhancements and advances in the properties of nano-structured glasses and composites in terms of thermal and mechanical properties. A fabrication method of nano-structured glass has briefly been discussed and the phase change material (PCM) method outlined. The comprehensive review of thermal and optical properties confirms that nano-fabricated glasses show both direct and indirect running of band gaps depending on selective nano-structuring samples. The electrical and magnetic properties also show enhancement in electrical conductivity on nano...
Research Interests:
Energy-efficient measures are being increasingly implemented in the building sector to reduce the increasing energy consumption with the growing population and the rapid development of urban building layouts. In hot and humid climates,... more
Energy-efficient measures are being increasingly implemented in the building sector to reduce the increasing energy consumption with the growing population and the rapid development of urban building layouts. In hot and humid climates, energy-saving measures for the building envelope elements have attracted increasing interest in research and practice due to their effectiveness in upgrading the building energy performance by reducing the amount of heat gain and solar glare to the building’s indoor environments. Accordingly, as evidenced by our review of the literature, an increasing number of publications on energy-saving measures for the building envelope are being published in peer-reviewed articles. However, a few literature overviews covering all possible energy-saving measures of building envelope elements, which can provide insight into determining the value of their effective parameters to achieve the best performance and evaluate the feasibility of energy efficiency improvem...
Research Interests:
The domains of energy, thermofluids, power systems, energy storage, materials, cooling, heating, and lubrication can all benefit from the prediction of viscosity's nanofluids. The present study aims to predict the dynamic... more
The domains of energy, thermofluids, power systems, energy storage, materials, cooling, heating, and lubrication can all benefit from the prediction of viscosity's nanofluids. The present study aims to predict the dynamic viscosity of Polyalphaolefin-Hexagonal boron nitride (PAO/hBN) nanofluids via four parameters: shear rate, shear stress, nanomaterials mass fraction, and temperature. Moreover, the current research implemented three Ensemble Learning models such as (Bayesian Ridge+ Random Forest), (MLP Regressor+ Bayesian Ridge), and (Bayesian Ridge+ AdaBoost Regressor). Different input combinations were constructed based on Forward Sequential Feature Selector (FSFS). The developed Model-4 showed the best estimation accuracy, followed by Model-2, Model-3, and Model-1. The computational findings showed that, Ensemble Learner-1 was slightly higher than Ensemble Learner-3. Meanwhile, Ensemble Learner-2 was always in the third order among the predictive models. Furthermore, the research results demonstrated that creating predictive models based on all of the input characteristics is capable of producing a precise prediction matrix. Overall, the study offered interesting conclusions on how to estimate a nanofluid's viscosity for uses in lubrication and heat transfer.
Research Interests:
Building retrofit procedures play a crucial role in improving the energy performance and economic indicators of a building. In this context, an energy audit is typically recommended, but it is seldom used as a comprehensive approach due... more
Building retrofit procedures play a crucial role in improving the energy performance and economic indicators of a building. In this context, an energy audit is typically recommended, but it is seldom used as a comprehensive approach due to the complexity and associated costs. This article aims to conduct a holistic energy audit approach for a university building in Malaysia, with the objective of diagnosing energy efficiency deficiencies, identifying areas of energy waste and proposing practical retrofit measures accordingly. The approach involved multiple stages, including measurements, surveys and simulation work. Eight energy-saving measures were proposed, targeting improvements in envelope elements, cooling and lighting systems, and operation and control. The Design-Builder software was utilized for energy simulation, assessing the annual energy savings. Economic evaluation indices, such as net present value and simple payback period, were used to assess the economic feasibility of the measures. The results demonstrated significant potential for energy reduction, with each measure achieving annual energy reductions ranging from 2% to 18%, and a cumulative impact of 41% on annual energy consumption when combined. The investment payback period for the energy-saving measures varied from 0.8 to 8.9 years, with a payback period of 3.9 years for the combined energy-saving measures. Furthermore, the net present value was positive, indicating the economic feasibility of investing in the proposed energy-saving measures. These findings provide valuable energy-saving opportunities that can be applied to improve similar buildings on the university campus.
Research Interests:
Research Interests:
In this paper, a novel multi-objective evolutionary artificial neural network approach is proposed to predict the performance of an automotive air conditioning (AAC) system. A Feedforward Neural Network (FNN) was used to simulate the... more
In this paper, a novel multi-objective evolutionary artificial neural network approach is proposed to predict the performance of an automotive air conditioning (AAC) system. A Feedforward Neural Network (FNN) was used to simulate the cooling capacity and compressor power under different combination of input compressor speeds, evaporator inlet air speeds, air temperature upstream of the condenser and evaporator. Differential Evolution (DE) algorithm was employed to automatically optimize the FNN's parameters, involving the number of hidden layers and the number of neurons in each hidden layer. The training of connection weights and biases is carried out using the basic backpropagation algorithm with Levenberg Marquardt nonlinear optimization method. For the purpose of multi-objective optimization, the DE algorithm is incorporated with two key elements of the NSGA-II (Non-dominated Sorting Genetic Algorithm II), namely the non-dominated sorting method and the crowding distance metric. A parametric study was performed on the proposed algorithm and the best DE base variant was determined. The experimental results show that the proposed algorithm with DE based variant ‘DE/Best/1’ exhibited its superiority in term of prediction performance. The best neural network obtained is FNN with 4×18×2 network configuration and its network complexity is equivalent to 108 connection weights. It yields an average relative error of 0.60% for the prediction of cooling power and one of 3.0% for the prediction of compressor power.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This paper presents the application of Extremum Seeking (ES) algorithm in auto tuning of an incremental proportional-integral-derivative (PID) controller in order to achieve optimal cabin temperature control of an automotive air... more
This paper presents the application of Extremum Seeking (ES) algorithm in auto tuning of an incremental proportional-integral-derivative (PID) controller in order to achieve optimal cabin temperature control of an automotive air conditioning (AAC) model. A mathematical nonlinear model of an AAC system with variable speed compressor is first developed. The AAC model consists of a condenser, evaporator, thermal expansion valve, variable speed compressor driven by a direct current (DC) motor and a vehicle cabin. The ES algorithm is introduced and used to tune the parameters of the PID controller via iterative step function simulation. Finally, step response tests show that PID controller delivers better performance after being tuned by ES algorithm.
Research Interests: Engineering, Optimal Control, Iterative Methods, Atmospheric Modeling, Heat Transfer, and 14 moreAutomotive Industry, Air Conditioning, Compressors, Dynamic Modeling, Valves, Pid Controller, Mathematical Model, Tuning, Evaporator, Heating, Thermal Expansion, Refrigerants, Condenser, and Step Response
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Burn injury is a common injury that can occur in firefighting. Personal protective clothing is used for protection against fire hazards and burn injuries. The purpose of this study is to assess the effectiveness of fire fighter’s personal... more
Burn injury is a common injury that can occur in firefighting. Personal protective clothing is used for protection against fire hazards and burn injuries. The purpose of this study is to assess the effectiveness of fire fighter’s personal protective clothing by utilizing heat transfer model in finite element analysis. The model used a 2 dimensional quarter circle geometry representing the human limb as it is the most common area for burn injury. The result shows skin temperature increases significantly with the heat flux intensity. Findings shows that the heat flux of 1200W/m2 causes skin temperature to be at 38.3oC. The initial skin temperature will gradually rise at t = 0 second and approaches it’s steady at t =198 seconds. The increment in air gap thickness reduces the heat stress effect. The reduction of 1 mm air gap thickness contributes to an increment of 0.2oC of the skin temperature
Research Interests:
A ceiling fan is a commonly used mechanical device for promoting airflow inside an enclosed space, for thermal comfort purposes. However, it is difficult to clean and maintain, noisy and sometimes can be dangerous to occupants. Recently,... more
A ceiling fan is a commonly used mechanical device for promoting airflow inside an enclosed space, for thermal comfort purposes. However, it is difficult to clean and maintain, noisy and sometimes can be dangerous to occupants. Recently, a high-volume low-speed fan (HVLS) was introduced as an alternative device to provide better air movement at a lower energy cost. This study aims to compare the distribution of airflow velocity produced by a single HVLS fan and that produced by two ceiling fans inside a room, using computational fluid dynamic (CFD) method. Two simplified models of two similar rooms were developed using commercial CFD software. One is furnished with an HVLS fan and the other with two ceiling fans. Steady-state flow simulations were performed on the CFD models using a Spalart-Allmaras turbulence airflow model and adopting a moving reference frame (MRF) technique. The CFD models were validated based on experimental data obtained from the literature. It was found that for a single HVLS fan operating at a rotational speed of 140 RPM, the average airflow velocity on a horizontal plane at 1.1 m height from the floor is around 0.87 m/s. This value falls within the range stated in the ASHRAE-55 standard for good thermal comfort. For the room furnished with two ceiling fans operating at the same rotational speed, the average airflow velocity on the similar horizontal plane is around 0.19 m/s, which is outside the limit specified in the ASHRAE-55 standard. But when the two ceiling fans were operated at a rotational speed of 300 RPM, the average airflow velocity on the plane increases to 0.42 m/s, which satisfies the ASHRAE Standard-55 requirement. These findings suggest that a single HVLS fan would provide a more desirable air movement inside a confined space thereby would promote a much better feeling of thermal comfort to the occupants, as compared to the use of two ceiling fans operating at a much higher rotational speed.
Research Interests:
ABSTRACT
Research Interests:
This paper presents an investigation on the effects of using solar chimney, gable vent, and the combination of the two natural ventilations on the average air temperature and air-flow condition inside a double-storey house in Malaysia,... more
This paper presents an investigation on the effects of using solar chimney, gable vent, and the combination of the two natural ventilations on the average air temperature and air-flow condition inside a double-storey house in Malaysia, using computational fluid dynamics (CFD) method. The representative model of the house comprises of a main hall, a kitchen and an upper hall. Both temperature and air velocity boundary conditions were prescribed on the model. Results of the simulation indicates that the average temperature of the air in the house at 1 pm closely matched the measured values. It was found that the average temperature of the air in the house is not so significantly affected by the types of natural ventilation used. Opening the kitchen door causes the air to flow from the main and upper halls towards the kitchen and causing a bottle neck at the pathways. A more uniform air flow is obtained when solar chimneys are used. When gable vents are used, high intensity air flow occurs in the main hall and it spreads uniformly towards the kitchen and upper hall. The air-flow intensity becomes even higher in the main and upper halls when a combination of solar chimney and gable vents are incorporated into the CFD model