Mansour Al Qubeissi

This study presents a surrogate-based aerothermal optimization of a High-Pressure Turbine (HPT) stage, subject to realistic nonuniformities in combustor-exit temperature and velocity. Specifically, for a combustor-to -nozzle-guide-vane (NGV) count ratio of 1:2, the two NGVs are shaped independently to accommodate inlet flow non-uniformity. A surrogate model based on steady-flow CFD samples is constructed and coupled with a Genetic Algorithm (GA) to optimize NGV lean parameters under coupled thermal and swirl inlet non-uniformities. The objective function was formulated based on the total-temperature distribution at the NGV exit, which was identified as the primary driver of rotor tip (RT) heat flux. The optimized unequal vane pairing resulted in a significantly cooler heat flux pattern across the RT and casing region. This avoided costly, unsteady CFD runs by training the surrogate on steady RANS samples. This thermal improvement is attributed to a favorable redistribution of the NGV exit temperature and a modified streamline topology of the rotor blade (pressure side). Furthermore, the optimized geometry yielded an increase in overall stage aerothermal efficiency of 1.7%.

1. The transportation sector is a major contributor to global greenhouse gas emissions, a central driver of climate change. Electric vehicles (EVs) emit only 200 g CO₂ per mile, compared to more th...

Effective battery thermal management system (BTMS) is critical for lithium-ion battery (LIB) safety and performance in electric vehicles. This study presents a CFD-driven optimisation framework for an immersion cooling BTMS using sustainable palm biodiesel as coolant. A conjugate heat transfer model for a 3S2P pouch cell module (20 Ah LiFePO₄) is developed and validated against experimental data (max < 29.9°C, Δ T < 5°C, and Δ P < 145.275 Pa (at 5C and 0.05 m/s).

This research work investigates the effects of adding ethanol to biodiesel–diesel blends on the performance and emissions of a single-cylinder, four-stroke, air-cooled compression-ignition engine. The engine was half-loaded within a speed range of 1000–2500 rpm. Four different fuel blends are considered: B0 (no biodiesel or ethanol), B10 (10% biodiesel), B10E2.5 (10% biodiesel with 2.5% ethanol), and B10E5 (10% biodiesel with 5% ethanol). The findings show that adding biodiesel slightly affects the engine power at low and medium speeds but increases power by approximately 6% at high speeds. Ethanol addition has a more significant impact, with an increase in engine power of 16% at 1700 rpm and 13% at 2500 rpm for 2.5% and 5% ethanol blends, respectively. All blends show an increase in brake mean effective pressure (BMEP) compared to B0, with the maximum enhancement observed in B10 with an average increase of 13% across all speeds. Specific fuel consumption is reduced with both biodiesel and ethanol addition, with a slight advantage for biodiesel, particularly at low and medium speeds. Thermal efficiency shows a reverse behaviour, with a small negative impact of ethanol addition. Biodiesel addition significantly increases carbon monoxide (CO) emissions, reaching an average of 190% across all speeds. However, adding ethanol helps mitigate this increase, especially at low and medium speeds, with an average decrease of 32% for a 2.5% ethanol blend compared to B0. Carbon dioxide (CO₂) and nitrogen oxides (NO_x) emissions are reduced with biodiesel addition and further reduced with ethanol addition. Overall, CO₂ and NO_x emissions are reduced with both biodiesel and ethanol addition.