论文部分内容阅读
Hydraulic hybrid propulsion is a solution to improve greenhouse emissions of vehicles.Power density,ability to allow new engine concepts,like free piston with improved thermodynamic cycles,capability for the internal combustion engine to run at constant,and here after low emission conditions,also the ability to recover different sizes of energy and last but not least,using conventional technology and applicability on all vehicles,even it is bicycle,micro mobility dedicated,conventional or heavy duty are arguments to further improve efficiency and technical solutions.A development solution for hydraulic hybrid propulsion systems is based on the principle that the column of liquid that transfers the energy is involved in an alternate movement and is not flowing continuously,just oscillating about an average value.The paper presents the performances of an off road vehicle,Dacia Duster,equipped with an alternant hydraulic transmission system.The hydraulic circuit is designed to allow dynamic phenomena,like inertia and accumulating effects to increase the energy concentration for low dissipation rates.After designing the working principle of the alternant hydraulic generator and motor,flow is optimized using a Lattice Bolzmann CFD software,to identify under source of flow loss under dynamic conditions.1D CFD and multi-physics simulation is used in order to design the hydraulic circuit.A test rig model is used to validate the concept under real running conditions.Particular attention is given to the leak-pressure wave relation.The test rig model is adapted to the vehicle and dynamic performances evaluated and compared to the base model.