Aman Mohd Ihsan Mamat | Universiti Teknologi Mara (original) (raw)

Papers by Aman Mohd Ihsan Mamat

Thermal enhancement through application of nanofluid coolant in a single cooling plate of Proton ... more Thermal enhancement through application of nanofluid coolant in a single cooling plate of Proton Exchange
Membrane (PEM) fuel cell was experimentally investigated in this paper. The study focuses on low concentration of
Al2O3 dispersed in Water - Ethylene Glycol mixtures as coolant in a carbon graphite PEM fuel cell cooling plate. The
study was conducted in a cooling plate size of 220mm x 300mm with 22 parallel mini channels and large fluid
distributors. The mini channel dimensions are 100mm x 1mm x 5 mm. A constant heat load of 100W was applied by
a heater pad that represents the artificial heat load of a single cell. Al2O3 nanoparticle used was 0.1 and 0.5 vol %
concentration which was then dispersed in 50:50 (water: Ethylene Glycol) mixture. The effect of different flow rates
to heat transfer enhancement and fluid flow represented in Re number range of 20 to 120 was observed. Heat transfer
was improved up to 13.87% for 0.5 vol % Al2O3 as compared to the base fluid. However the pressure drop also
increase which result in pumping power increment up to 0.02W. The positive thermal results implied that Al2O3
nanofluid is a potential candidate for future applications in PEM fuel cell thermal management.

Numerical analysis of thermal enhancement for a single Proton Exchange Membrane Fuel Cell (PEMFC)... more Numerical analysis of thermal enhancement for a single Proton Exchange Membrane Fuel Cell (PEMFC) cooling
plate is presented in this paper. A low concentration of Al2O3 in Water - Ethylene Glycol mixtures was used as
coolant in 220mm x 300mm cooling plate with 22 parallel mini channels of 1 x 5 x 100mm. This cooling plate
mimicked conventional PEMFC cooling plate as it was made of carbon graphite. Large header was added to have an
even velocity distribution across all Re number studied. The cooling plate was subjected to a constant heat flux of
100W that represented the artificial heat load of a single cell. Al2O3 nano particle volume % concentration of 0.1 and
0.5 vol was dispersed in 50:50 (water: Ethylene Glycol) mixtures. The effect of different flow rates to heat transfer
enhancement and fluid flow in Re range of 30 to 150 were observed. The result showed that thermal performance has
improved by 7.3 and 4.6% for 0.5 and 0.1 vol % Al2O3 consecutively in 50:50 (water:EG) as compared to base fluid
of 50:50 (water:EG). It is shown that the higher vol % concentration of Al2O3 the better the heat transfer
enhancement but at the expense of higher pumping power required as much as 0.04W due to increase in pressure
drop. The positive thermal results implied that Al2O3 nanofluid is a potential candidate for future applications in PEM
fuel cell thermal management

Polymer Electrolyte Membrane Fuel Cells (PEMFC) operation is sensitive to micro electrochemical c... more Polymer Electrolyte Membrane Fuel Cells (PEMFC) operation is sensitive to micro electrochemical changes and can
only tolerate a small temperature variation for optimal power generation. An effective cooling system is needed to
comply with this condition. Nanofluids are perceived as a potential coolant for thermal management in PEMFC
application that allows for more compact design. The dispersion of nanofluid in water-ethylene glycol base fluid
enhances the thermal conductivity for improved heat transfer. The thermal conductivity, viscosity and electrical
conductivity of different Silicon Dioxide (SiO2) concentrations diluted in Ethylene Glycol/Water (EG/W) mixtures of
40EG, 50EG and 60EG are reported. However, the electrical conductivity would contribute to electrical leakage and
is a limiting factor for fuel cell operation. Highest value of thermal conductivity recorded is the dispersion of
nanofluid in 40EG whereas the viscosity of SiO2 is the highest in 60EG dilution. Electrical conductivity is recorded
the highest in EG/W 40:60% with 0.5% of SiO2. However, the electrical conductivity would contribute to electrical
leakage and is a limiting factor for fuel cell operation.

Continuous need for the optimum conversion efficiency of polymer electrolyte membrane fuel cell (... more Continuous need for the optimum conversion efficiency of polymer electrolyte
membrane fuel cell (PEMFC) operation has triggered varieties of advancements,
namely in the thermal management engineering scope. Excellent heat dissipation is
correlated with higher performance of a fuel cell, thus increasing its conversion
efficiency. This study reveals the potential advancement in thermal engineering of a fuel
cell cooling system with respect to nanofluid technology. Nanofluids are seen as a
potential evolution of nanotechnology hybridization with the fuel cell serving as a
cooling medium. The available literature on the thermophysical properties of potential
nanofluids, especially on the electrical conductivity property, has been discussed. The
lack of electrical conductivity data for various nanofluids in open literature was another
challenge in the application of nanofluids in fuel cells. Unlike in any other thermal
management system, a nanofluid in a fuel cell is dealt with using a thermoelectrically
active environment. The main challenge in nanofluid adoption in fuel cells was the
formulation of a suitable nanofluid coolant with heat transfer enhancement, as compared
to its base fluid, but still complying with the strict limits of electrical conductivity as
low as 2 S/cm and several other restrictions discussed by the researchers. It is
concluded that a nanofluid in PEMFC is advantageous in terms of both heat transfer and
simplification of the cooling system through radiator size reduction and potential
elimination of the deionizer as compared to the current PEMFC cooling system.
However, there are challenges that need to be well addressed, especially in the electrical
conductivity requirement

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES, 2014

Procedia Engineering, 2013

This study discusses on the fuel economy and exhaust emissions at variations of air intake pressu... more This study discusses on the fuel economy and exhaust emissions at variations of air intake pressure. The air intake pressure is influenced by the degree of opening throttle plate and venturi effect which draw the fuel to the combustion chamber in carbureted engine. The experimental work is conducted at variations of engine speed and load using a single cylinder four stroke SI engine attached with 5kW dynamometer. Gas analyzer was used to measure exhaust emissions compositions and to identify the quality of combustion. The results show that the standard air intake system resulted in rich combustion which led to the incomplete combustion due to less availability of air. By eliminating the air filter, the air flow restriction through the air intake system was reduced. Hence, better combustion and less unburned components are achieved because of higher air availability. A higher air intake pressure is required to increase air density in allowing for better combustion within a limited time to improve fuel economy, power output and exhaust emissions. Complete combustion also lead to the reduction of unburned components such as carbon (C), hydrogen (H 2 ), carbon monoxide (CO) and hydroxide (OH) that resulted in less hazardous emissions.

Abstract. Waste heat recovery in automotive engineering is part of the sustainable energy effort ... more Abstract. Waste heat recovery in automotive engineering is part of the sustainable energy effort to optimize energy utilization. For vehicles running on hydrogen fuel cells, the potential of heat recovery is perceived to be limited due to the low quality energy generated from the fuel cell stack. It has been established in fuel cell operation that increasing the inlet hydrogen temperature improves the conversion efficiency through higher kinetic reaction rates. A fuel cell power plant for a mini vehicle that will be competing in Shell Eco Marathon Asia 2014 was studied to identify the potential energy recovery limits for an improved power plant design with regenerative hydrogen pre-heater. Using modeling approach for fuel cell power generation and efficiency relationships, the first-order waste energy potential was identified based on test bench studies on the electrical and thermal power relationship of the fuel cell stack performance. The corresponding result is then mapped to a driving cycle to investigate the thermal power generated during the race in both aggressive and passive driving cycle. The energy recovery potential for 4 laps course under aggressive and passive driving cycle are 529 kJ and 501.8 kJ consecutively. The mean thermal powers are 485 W and 410 W respectively which is the reference energy for extended heat exchanger design purposes.

Waste heat recovery in automotive engineering is part of the sustainable energy effort to optimiz... more Waste heat recovery in automotive engineering is part of the sustainable energy effort to optimize energy utilization. For vehicles running on hydrogen fuel cells, the potential of heat recovery is perceived to be limited due to the low quality energy generated from the fuel cell stack. It has been established in fuel cell operation that increasing the inlet hydrogen temperature improves the conversion efficiency through higher kinetic reaction rates. A fuel cell power plant for a mini vehicle that will be competing in Shell Eco Marathon Asia 2014 was studied to identify the potential energy recovery limits for an improved power plant design with regenerative hydrogen pre-heater. Using modeling approach for fuel cell power generation and efficiency relationships, the first-order waste energy potential was identified based on test bench studies on the electrical and thermal power relationship of the fuel cell stack performance. The corresponding result is then mapped to a driving cycle to investigate the thermal power generated during the race in both aggressive and passive driving cycle. The energy recovery potential for 4 laps course under aggressive and passive driving cycle are 529 kJ and 501.8 kJ consecutively. The mean thermal powers are 485 W and 410 W respectively which is the reference energy for extended heat exchanger design purposes.

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES, 2014

Procedia Engineering, 2013