CAJ | 학술논문

利用GT-Power软件建立仿真模型，开展了进排气压力波动分析，针对全负荷7个稳态转速点，研究了扫气量和进排气压差的关系，确定了可用扫气转速区域。分别在最大扭矩工况和标定功率工况探讨了气门正时对发动机性能的影响规律，并提出了全负荷工况气门正时优化策略。研究结果表明：在1000～2700 r/min转速范围内，排气上止点附近存在进排气正压差区，扫气系数大于1．03；在最大扭矩工况，增大气门重叠角，可使扫气系数增加，涡前排温明显下降；在标定功率工况，排气门关闭正时在353°A T DC附近时，残余废气系数最小。基于进气量优化气门正时，在全负荷6000 r/min处，进气量提高了19％，残余废气系数降低了0．018，功率提升了21％。在最大扭矩工况附近，增压压力提高了11．7％，涡前压力增大了19．4％。
이용GT-Power연건건립방진모형，개전료진배기압력파동분석，침대전부하7개은태전속점，연구료소기량화진배기압차적관계，학정료가용소기전속구역。분별재최대뉴구공황화표정공솔공황탐토료기문정시대발동궤성능적영향규률，병제출료전부하공황기문정시우화책략。연구결과표명：재1000～2700 r/min전속범위내，배기상지점부근존재진배기정압차구，소기계수대우1．03；재최대뉴구공황，증대기문중첩각，가사소기계수증가，와전배온명현하강；재표정공솔공황，배기문관폐정시재353°A T DC부근시，잔여폐기계수최소。기우진기량우화기문정시，재전부하6000 r/min처，진기량제고료19％，잔여폐기계수강저료0．018，공솔제승료21％。재최대뉴구공황부근，증압압력제고료11．7％，와전압력증대료19．4％。
Based on the calculated model established by GT-Power software ,the intake and exhaust pressure fluctuation was analyzed .The speed range of available scavenging was determined by analyzing the relation of scavenging mass with intake and exhaust pressure difference in seven operating conditions .The effect of valve timing on engine performance was discussed in conditions of maximum torque and rated power and the optimization strategy of valve timing in full load was put forward .The results show that the positive pressure difference exists and the scavenging coefficient is 1 .03 near exhaust TDC in 1 000~2 700 r/min .In the maximum torque condition ,increasing valve overlap angle can increase the scavenging coefficient and the temperature before the turbine will decrease .In the rated power condition ,the coefficient of residual gas reaches the minimum when EVC is around 353°ATDC .After optimizing the valve timing ,the intake air mass increases by 19% ,the coefficient of re-sidual gas decreases by 0 .018 and the power increases by 21% in full load condition of 6 000 r/min .In the maximum torque condition ,the pressure after compressor improves by 11 .7% and the pressure before turbine increases by 19 .4% .