Model-based optimization of Sliding Rotary Vane Pump for internal combustion engine cooling of heavy-duty vehicles

The reduction of CO2 and pollutant emissions of internal combustion engines (ICEs) keeping their performance close to the expectations is the main driver of the research in the transportation sector. To counteract the global warming issues international governments set strict emission limitations foreseeing severe penalties for exceeding them. The vehicle electrification surely helps to match these stringent requirements, but a net CO2 reduction can be achieved only if the electricity from the grid has low carbon content. This is not the case of most part of the Countries where the fossil fuels are still the main sources of electric energy production. Thus, considering also the still higher cost of the electric vehicles, the technological improvement of ICEs assumes a strategic importance in this transition period. Among the possible interventions ensuring to achieve this aim, the efficiency enhancement of ICE cooling pump is one of the most effective. As matter of fact, it is proven that the replacement of conventional centrifugal pump with Sliding Rotary Vane Pumps (SVRPs) lead to an interesting decrease of fuel consumption and CO2 emissions. Nevertheless, the design of this machines is not straightforward due to the complex thermo-fluid-dynamic phenomena taking place inside their chambers. This aspect is even more critical for wide operating range as in the case of heavy-duty vehicles. Here, high pump revolution speeds could be provided to satisfy the flow rate requirements thus involving efficiency deterioration due to friction losses enhancement. Therefore, to reduce the revolution speed needed by the pump to elaborate the required flow rate, a novel design strategy based on the enhancement of volumetric capability is presented. The pump resulting by this design approach was called Low Speed LS pump which was prototyped and experimentally characterized over a wide set of operating conditions. The indicated cycle was also measured to better assess the fluid-dynamic behaviour of the machine. The experimental results show a maximum efficiency close to 60% in accordance with the best literature results.