The Quasi-Propagatory Model (QPM), a new approach to simulate fluid transients in duct systems, is presented in this paper. The model fills the gap existing between lumped-parameter and distributed-parameter models, allowing the simulation of propagatory effects, even in a compact, lumped-parameter framework. The model, previously developed for homentropic flows, is extended here to include the presence of section variations, friction and heat flows. This is done without substantially altering the model architecture. A theoretical and an experimental validation of the QPM have been carried out. Test cases have been run and the results compared with those yielded by the Method of Characteristics, which was taken as a reference model. Moreover, the model predictions were also compared with experimental data measured in a pipe test rig.

One of the biggest barriers towards large scale adoption of electric and plug-in hybrid cars is still range limitation due to limited storage capacity of electric batteries. The air conditioning system for passenger comfort and the thermal conditioning system (battery and powertrain) are critical auxiliary consumers in electric vehicles with respect to energy consumption. Therefore, the Horizon 2020 project “OPTEMUS” proposes to tackle this bottleneck by leveraging heat pump technology and a holistic thermal system optimization approach. This paper presents the optimization strategy used for energy-efficient cabin conditioning in cold weather condition and simulation results of the air conditioning system including a heat pump. This system is capable of using the ambient air or a preconditioned battery as heat source, thus significantly reducing overall energy consumption.