CA4DD Series Engine Pefrormance Design And Development Based On Vehicle Performance Requirement

Emission regulations and vehicle energy reduction requirements continuouspushed forward engine technological progress, majority innovation of combustiontheory could not be applied to the production due to various constraints, it became afocus of energy saving and emission reduction that engine performance design anddevelopment took aim at vehicle application characteristics. In traditional vehicledevelopment process, vehicle and engine is developed separately by the twodepartments, and vehicle performance test after engine finished its development work,engine result usually could not meet vehicle performance demands in verificationprocess, repeated work must be done in engine performance modification and vehiclevalidation, it was time and costs consuming. This thesis presented a "V " shapedpositive vehicle development process and established a vehicle and engineco simulation platform, it was used to decompose vehicle performance requirement toengine target in performance design process and to evaluate if vehicle performancewas met in engine development process, a positive development process could beachieved, so that engine performance was under control from vehicle point of view. Apositive development process from engine to sub system was built either within CAEsupport, for sub system, works can be done that engine performance decomposed tosub system in design and evaluate engine result in development period. Positivedevelopment process was used for CA4DD series engine performance design andperformance development, vehicle testing datas were taken to evaluation of theeffectiveness co simulation platform. The main research contents and conclusions wassummarized as follows:1. Vehicle and engine performance co simulation platform software GT Suiteand Simulink was introduced, Co simulation platform for CA4DD series engine wasestablished and corresponding vehicle boundary conditions was given. Builtsimulation model and calibration work was done with3different simulation modes(static, kinematics and dynamic), Simulation model calibration work was done with3different simulation modes, ensure the error between test and simulation result within5%in stedy state silulation. Transient simulation model was developed base on steadystate model.2. Theoretical analysis on corresponding relationship between vehicle and engineperformance was discussed, key factors that affecting performance of engineperformance and vehicle fuel economy was found out. A positive "V" shaped positiveprocess from vehicle to engine and then subsystem was described in detail, defineeither work method or means of the precess.3. Vehicles corresponding to CA4DD series engine was simulated usingco simulation platform, static force analysis was done to define engine full load torque and power, kinematic simulation to define emission control and high operatingefficiency area, the area would be performance foucs in engine design anddevelopment. Engine performance parameters were settled down according simulationresults, then combustion and in cylinder flow conditions were simulated using StarCDsoftware, combustion concept was put forward according performance requirements,fuel supply system, gas exchange system and in cylinder combustion organize targetwas defined through engine proformance subdivition. Subsystem include valvetrainparameter, turbocharger, EGR, intake swirl and combustion chamber were work outwithin support of CAE tools, performance prediction result shown that subsystemdesign could satisfy engine performance requirements.4. Performance test was carried out to compare and analysis differentdevelopment scheme, combustion development scheme ultimately determined ofCA4DD series3type engines. Detailed calibration was done in stereotypes engineswhich determined by testing, performance results were released finally, results shownthat performance targets could be achieved. Vehicle performance was evaluated usingco simulation platform, results shown that CA4DD1and CA4DD3engines could metvehicle defined target, vehicle corresponding to CA4DD2engine accelerationperformance was not achieved （11.2%worse）with a fixed geometry turbocharger,VGT matching and control strategy optimized using dynamic simulate mode ofco simulation platform, target was reached finally with2.3%higher than target.Performance of vehicle with CA4DD1engine was tested, results shown thatmaximum vehicle speed error was2.8%, fuel consumption error of top gare80km/hand WTVC were respectively1.4%and1.9%, top gare acceleration and shift gareacceleration response time error were14.3%and4.1%. Steady state error between testand simulation within acceptable range5%, transient response time error withinacceptable error range15%. It improved that vehicle and engine co simulationplatform were reliable, realizing vehicle and engine positive development by usingco simulation platform and other engine CAE tool was feasible.This paper presented a vehicle and engine positive development "V " shapedprocess, and established a vehicle and engine co simulation platform as an importantmeans to realize this process, realized positive development process in CA4DDengine development project, engine performance could be designed and developedaiming at vehicle performance, disadvantages in traditional process of adjustment andvalidation repeatedly were changed, positive process could saved development timeand costs thus improved product competitiveness.