【摘要】 以一款燃烧RP-3航空煤油的直列四冲程压燃式发动机为研究对象，建立了三维燃烧模型，并基于三维燃烧模型的边界条件建立了活塞与内冷油腔双向耦合模型。在喷油参数和压缩比相同的情况下，对ω型燃烧室（omega combustion chamber, OCC）、双旋涡碗型燃烧室（double swirl bowl combustion chamber, DSBCC）、加深型燃烧室（deepened combustion chamber, DCC）及浅型凹入式燃烧室（shallow re-entrant combustion chamber, SRCC）4种不同类型燃烧室进行了对比研究。研究分析了燃烧室类型对缸内当量比分布、指示热效率、活塞温度场及活塞热机耦合应力等的影响。研究结果表明，与原机OCC结构相比，DSBCC、DCC及SRCC结构的当量比分布更均匀，指示热效率均得到了明显提升，分别提升了0.93、1.48和2.44个百分点。DSBCC、DCC和SRCC结构的活塞最大温度分别增大了4.39%、1.26%及47.89%。DSBCC结构活塞的最大热机耦合应力降低了1.24 MPa,DCC和SRCC结构活塞的最大热机耦合应力分别增大了16.57 MPa和76.11 MPa。更多还原

【Abstract】 A three-dimensional combustion model was established for a direct-injection four-stroke compression ignition engine fueled with RP-3 aviation kerosene. Based on the boundary conditions of the threedimensional combustion model, a bidirectional coupling model of the piston and piston cooling gallery was developed. Under the same injection parameters and compression ratio, a comparative study was conducted on four types of combustion chambers including omega combustion chamber(OCC), double swirl bowl combustion chamber(DSBCC), deepened combustion chamber(DCC) and shallow re-entrant combustion chamber(SRCC). The effects of combustion chamber type on the in-cylinder equivalence ratio distribution, indicated thermal efficiency, piston temperature field, and piston thermo-mechanical coupling stress were analyzed. The results show that compared to the original OCC structure, the DSBCC, DCC, and SRCC structures have more uniform equivalence ratio distribution and significantly improved indicated thermal efficiency, with increases of 0. 93, 1. 48 and 2. 44 percentage points, respectively. The maximum piston temperatures for DSBCC, DCC and SRCC structures increase by 4. 39%, 1. 26% and 47. 89%, respectively. The maximum thermo-mechanical coupling stress on the piston of the DSBCC structure reduces by 1. 24 MPa, while those of the DCC and SRCC structures increase by 16. 57 MPa and 76. 11 MPa, respectively.更多还原