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In the present investigation, a parametric study of the geometric characteristics of a two-cylinder four-stroke gasoline engine was carried out. Engine power, torque, specific consumption, engine efficiency, in-cylinder pressure for both the cylinders and pressure along the intake and exhaust manifolds at different positions were experimentally measured for engine speeds ranging from 5000 to 9500 rpm. All measurements were made under steady state conditions and full load. Engine characteristics were calculated by means of a 1-D model, which was used to calculate wave propagation in the intake and exhaust manifolds. A zero dimensional model was used to account for the in-cylinder phenomena. In the 1-D model the effects of pipe curvature, restriction geometry, gas friction, and heat transfer to the manifolds walls were considered. Numerical results showed good agreement with the measurements over the investigated range of operating conditions.

This experimental study investigates the thermal behavior of a 48V lithium-ion battery (LIB) pack comprising three identical modules, each containing 12 prismatic LIB cells. The objective is to investigate the thermal performance of the LIB pack under real-world operating conditions using a worldwide harmonized light duty test cycle and its inverted version. Two cases are tested whose difference is the initial state of charge (SOC), 90% for Case1 and 60% for Case2. The temperature distribution within the battery pack and cooling system is measured using 27 thermocouples. The results show that external surfaces exhibit the lowest temperatures, while the middle cells experience the highest. In addition, an abnormal temperature spike in a specific cell shows external influences or internal irregularities of the LIB cell, emphasizing the need to utilize a high number of thermocouples. Comparing Case1 and Case2, Case2 demonstrates a higher temperature rise at the cycle's beginning.

This study experimentally investigates the temperature distribution and behavior of a 48V Lithium-Ion (Li-ion) battery pack during two charge-discharge cycles using 25 thermocouples. Results indicate that better convective heat transfer occurs at the external surfaces of the pack, while middle cells reach maximum temperatures. Differences are also observed in the behavior of the three modules. The discharge cycle shows a temperature rise of 5.8°?? with a pack temperature gradient increasing from 1.3°?? to 2.7°??. The study highlights the importance of assessing the thermal behavior of each module and the complexity of the Li-ion battery pack system. Findings on the battery cells, modules, and pack in the same study can provide valuable insights for designing efficient cooling systems for Li-ion battery packs.