Sliding vane rotary pump in engine cooling system for automotive sector

The engine cooling system in internal combustion engines remained almost unchanged since many decades without significant modifications or improvements. Nevertheless, its revision, in terms of flow management among different vehicle's thermal needs, can play a crucial role in order to satisfy the recent and always more stringent commitments on emission reduction and fuel consumption saving. The engine cooling pump is, usually, mechanically linked to the engine. Its absorbed power can be till to the 5% of a mean power of a passenger car in a homologation cycle. During this cycle, it works always at operating conditions which are far away from the design condition, with a very low overall efficiency (15%e20%). If pump efficiency is a new technological goal, several reasons push towards a different pump type. A sliding vane rotary pump (SVRP) is a serious alternative having all the characteristics to fulfill the engine cooling circuit: these pumps are less efficiency sensitive to the revolution speed, flow rate and head. In this work, a sliding vane rotary pump has been designed for an existing engine cooling circuit. It has been built and extensively tested in order to compare its performances to a traditional (centrifugal) mechanical type. The model of this novel pump has been inserted in a wide and comprehensive mathematical model of the engine cooling system which behaved as engine virtual platform having been validated for the specific engine. The mechanical energy absorbed by the novel pump (and that by the traditional centrifugal one) has been calculated when the engine reproduced the international homologation driving cycles on which emission and fuel consumption are usually measured. The lower mechanical energy absorbed by the SVRP when compared to traditional type justifies a reduction of the order of 0.5 gCO2/km. This issue represents a very important result being today the engine technological development massively oriented to the fuel consumption saving