Halil S. Hamut

Experimental and Theoretical Efficiency Investigation of Hybrid Electric Vehicle Battery Thermal Management Systems

In this study, a thermodynamic model of a hybrid electric vehicle battery thermal management system (TMS) is developed and the efficiency of the system is determined based on different parameters and operating conditions. Subsequently, a TMS test bench is used with a production vehicle (Chevrolet Volt) that is fully instrumented in order to develop a vehicle level demonstration of the study. The experimental data are acquired under various conditions using an IPETRONIK data acquisition system, along with other reported data in the literature, to validate the numerical model results. Based on the analyses, the condenser and evaporator pressure drop, compressor work and compression ratio, evaporator heat load and efficiency of the system are determined both numerically and experimentally. The predicted results are determined to be within 6% of the conducted experimental results and within 15% of the reported results in the literature.

Effects of rear spoilers on ground vehicle aerodynamic drag

Purpose – The purpose of this paper is to examine the aerodynamic effects of rear spoiler geometry on a sports car. Today, due to economical, safety and even environmental concerns, vehicle aerodynamics play a much more significant role in design considerations and rear spoilers play a major role in this area. Design/methodology/approach – A 2-D vehicle geometry of a race car is created and solved using the computational fluid dynamics (CFD) solver FLUENT version 6.3. The aerodynamic effects are analyzed under various vehicle speeds with and without a rear spoiler. The main results are compared to a wind tunnel experiment conducted with 1/18 replica of a Nascar. Findings – By the CFD analysis, the drag coefficient without the spoiler is calculated to be 0.31. When the spoiler is added to the geometry, the drag coefficient increases to 0.36. The computational results with the spoiler are compared with the experimental data, and a good agreement is obtained within a 5.8 percent error band. The uncertainty a...

Exergoeconomic and Enviroeconomic Analyses of Hybrid Electric Vehicle Thermal Management Systems

Thermal management systems (TMSs) are one of the key components of hybrid electric vehicles in terms of their impact on vehicle efficiency, as well as the vehicle’s overall cost and environmental footprint. In this paper, exergoeconomic and enviroeconomic (environmental cost) analyses of hybrid electric vehicle thermal management systems are conducted with respect to various system parameters as well as operating conditions. In the exergy analysis, balance equations are applied to each system component of the TMS, in order to determine exergy destruction rates and calculate the exergy efficiencies of the system and its individual components. In the economic analysis, investment cost rates are calculated with respect to equipment costs, which are determined by cost correlations for each system component, and capital recovery factors. Thus, by combining the two analyses, an exergoeconomic model is created whereby the exergy streams are identified, fuel and productsare defined and cost equations are allocated for each component. The costs from the economic analysis are used to determine the unit cost of exergy, cost rate of exergy destruction as well as other useful exergoeconomic variables for each component. Moreover, an enviroeconomical (environment cost) analysis is also conducted based on the established carbon price associated with the released CO2 to the environment, corresponding to the indirect emissions from the electricity used in the TMS under varying carbon prices and electricity generation mixes.

Assessment of Desalination Technologies Integrated with Renewable Energy Sources in Turkey

In the past few decades, freshwater availability and quality for human consumption in the world has reduced significantly due to rapid population growth along with increasing industrial and agricultural demands, as well as uncontrolled urbanization and climate change. Even though Turkey is surrounded by water, its available freshwater per capita per year is less than the world average and much less that those for countries with developed economies [1]. Meanwhile, available freshwater sources in Turkey are diminishing rapidly due to pollution and overextraction associated with significantly increasing water demands. In order to prevent water scarcity in Turkey over the next decades, desalination is expected to be an important option. Appropriate desalination technologies need to be determined for implementation throughout the country.

Exergy Analysis and Environmental Impact Assessment of Using Various Refrigerants for Hybrid Electric Vehicle Thermal Management Systems

Thermal management systems (TMSs) are one of the key components of hybrid electric vehicles in terms of their impact on vehicle efficiency and performance, as well as the vehicle’s environmental footprint. In this chapter, an environmental assessment of hybrid electric vehicle thermal management systems is developed with respect to various refrigerants such as R134a, R600 (butane), R600a (isobutane), R1234yf (tetrafluoropropene) and dimethyl ether (DME). The energetic and exergetic COPs along with exergy destruction rates are analyzed for the TMS using each refrigerant. Also, greenhouse gas (GHG) emissions (in g CO2-eq/kWh) during operation and the sustainability index are determined under various system parameters, operating conditions, as well as carbon dioxide scenarios. Based on the results, all selected TMSs are determined to have higher energetic and exergetic COPs along with lower environmental impact than the baseline TMS (which uses R134a) except for the TMS using R1234yf. The highest efficiency and lowest environmental impact are achieved by TMS using DME with higher energetic and exergetic COPs (by 7.9 and 8.2 %, respectively) and lower GHG emissions (by 8.3 %) and higher sustainability index (by 3.3 %) than the baseline TMS.