CAJ | 학술논문

通过示功图计算和CFD数值模拟,针对液压自由活塞发动机燃烧过程的研究提出数值仿真迭代研究方法,从而分析控制参数与缸内工作过程的交互耦合影响关系.结果表明,与传统曲柄连杆发动机的活塞运动规律相比,当二者取相同喷油时刻或相同喷油位置时,在滞燃期内准备的混合气有所差异,HFPDE 的滞燃期较短,从而造成预混燃烧阶段放热率的差异.HFPDE 放热较快导致活塞加速较快,从而导致温度分布与传统发动机有所差异,温度随活塞快速膨胀而急剧下降导致了氮氧化物的产生主要集中在上止点附近,燃烧后期生成量较少;逆挤流对缸内空燃比的影响较大,使得碳烟生成在接近缸套附近的位置较为集中,而温度的快速下降使得其对碳烟的分布影响减弱.
통과시공도계산화CFD수치모의,침대액압자유활새발동궤연소과정적연구제출수치방진질대연구방법,종이분석공제삼수여항내공작과정적교호우합영향관계.결과표명,여전통곡병련간발동궤적활새운동규률상비,당이자취상동분유시각혹상동분유위치시,재체연기내준비적혼합기유소차이,HFPDE 적체연기교단,종이조성예혼연소계단방열솔적차이.HFPDE 방열교쾌도치활새가속교쾌,종이도치온도분포여전통발동궤유소차이,온도수활새쾌속팽창이급극하강도치료담양화물적산생주요집중재상지점부근,연소후기생성량교소;역제류대항내공연비적영향교대,사득탄연생성재접근항투부근적위치교위집중,이온도적쾌속하강사득기대탄연적분포영향감약.
Through the calculation of indicator diagram and CFD numerical simulation,in order to study the in-cylinder combustion process of hydraulic free-piston engine,the numerical simulation iteration method is pro-posed.Thus the control parameters and the interactive relationship between in-cylinder coupling parameters inthe working process can be analyzed.Results show that compared with the traditional crank-shaft engine,when the injec-tion timing or the injection location is the same,the mixture prepared during ignition delay period is different. The ignition delay period of HFPDE is shorter,which leads to the difference inpremixed combustion heat release rate.Rapid heat release causes fast piston movement,thus resulting in different in-cylinder temperature distribu-tion.Lower temperature causes NOx to concentrate on TDC. NOx is hardly produced after combustion.On the other hand,the influence of inverse extrusion flow on in-cylinder air-fuel ratio is great,soot is mainly formed near the cylinder liner,and the rapid decline of temperature makes less contribution to soot distribution.