Search Results

Thermal comfort in the vehicle cabin environment is an important factor for passengers of both internal combustion engines and electric vehicles. Heating, Ventilation and Air Conditioning (HVAC) is a critical system for electric vehicles (EVs) as it is the second most power consumer after electric motor. Novel solutions dedicated to EV, including thermoelectric air conditioning (AC) modules, vapor compression refrigeration (VCR), cycle positive temperature coefficient (PTC) heater as well as heat pumps (HP), are being investigated to maintain a stable and comfortable interior environment under hot and cold weather conditions. At present, the mostly dominated automotive AC systems are those using R134a refrigerant characterized by high global warming potential. Therefore, an innovative and ecofriendly AC system design still must be developed to supply sufficient cooling or heating capacity while minimizing the influence of the AC system on driving ranges and environmental performance.

Though CFD methods have become very popular and widespread tools in the early as well as more advanced automotive design stages, they are still not so common in the motorcycle industry branch. The present work aims at the development of a comprehensive simulation environment, based on the open-source finite volume toolbox OpenFOAM®, for the aerodynamic and thermal fluxes optimization of a full motorcycle-and-rider geometry. The paper is divided in two parts: in the first one, the OpenFOAM® code is evaluated for a cold flow aerodynamic analysis, using a slightly simplified version of the Aprilia RSV4 motorbike geometry; in the second one, a mixed reduced scale-full scale methodology is proposed for the simultaneous assessment of aerodynamic forces and heat transfer performances of the engine cooling system. Results have been compared against other well established commercial CFD packages and, where available, with experimental measurements.

Lithium ion batteries are the most promising candidates for electric and hybrid electric vehicles, owe to their ability to store higher electrical energy. As a matter of fact, in automotive applications, these batteries undergo frequent and fast charge and discharge processes, which are associated to internal heat generation, which in turns causes temperature increase. Thermal management is therefore crucial to keep temperature in an appropriate level for safe operation and battery wear prevention. In a recent work authors have already demonstrated the capabilities of a coupled lattice Boltzmann-Finite Volume Method to deal with thermal transient of a three-dimensional air-cooled Li-ion battery at different discharging rates and Reynolds numbers. Here, in order to improve discharge thermal capabilities and reduce temperature levels of the battery itself, a layer of porous medium is placed in contact with the battery so to replace a continuum solid aluminum layer.