Editorial: New developments in vehicle thermal management

Abstract

The role of transportation is essential in meeting international targets for increasing energy efficiency and reducing fossil fuel consumption. Thermal engines still dominate the propulsion systems of vehicles, making it imperative to improve their efficiency during the transition to more sustainable systems powered by green electricity and hydrogen.Among the various technologies being developed to achieve these goals, thermal management stands out as a cost-effective option. It proves to be appealing not only for traditional vehicles with thermal engines but also for hybrid and electric vehicles. This Research Topic aims to showcase the latest innovations in technologies, components, layouts, control management, and vehicle cabin conditioning. Thermal management options also encompass opportunities for energy recovery, which can significantly enhance the overall efficiency of vehicles. Furthermore, the integration of cabin conditioning and auxiliary systems into the vehicle's thermal management is relevant not only for traditional vehicles but also for hybrid, electric, and hydrogen-fueled vehicles and transportation means.In particular, this Research Topic in Frontiers of Mechanical Engineering contains four papers, including one review and three research articles, supplied by researchers from six countries. These papers cover broad areas, including recent advances in hybrid and electric vehicles lubrication and thermal management, waste heat recovery, thermal energy storages and the estimation of power demand of auxiliaries.Indeed, auxiliary engine loads have become a critical factor affecting powertrain performance and fuel economy. This is true both for thermal engines and for hybrid and electrified ones. In this regard, air conditioning, alternators, water pump and steering pump are the components that cannot be neglected. For a medium car (about 100 hp power), the contribution of the auxiliary loads can be more than 17% of the brake power (Gajanayake et al.), and it depends significantly on the operating and environmental conditions. Air conditioning systems usually consist of refrigerating units, where the compressor is driven by a belt linked to the engine crankshaft. During summer, the power absorbed can be significantly high when the cabin temperature approaches 40 °C or at low vehicle speeds, reducing the cooling of the condenser placed in the front end of the vehicle (Askar et al., 2023). Even the alternator is an energy-consuming component, and the progressive electrification of the vehicles claims for even more efficient electrical machines. The coolant pump is usually always active during the vehicle run since it has the fundamental role of delivering the coolant fluid to the engine and the other components of the powertrain, such as batteries, electronics and heater cores. The temperature control of these auxiliary components, which play a crucial role in the proper functioning of the vehicle, requires the coolant pump to be highly reliable, usually resulting in a general overdesign of this compo...