In this study, an Otto cycle engine was converted to the Atkinson cycle engine using the method of late intake valve closing and increasing the compression ratio. Firstly, the thermodynamic analysis was conducted. In the analysis, the variation of specific heats with temperature, heat losses, pumping, and mechanical friction losses was taken into account. In-cylinder pressure variations, torque, power, thermal efficiency and brake-specific fuel consumption variations with speed were obtained. For the experimental study, a new camshaft was designed and manufactured using a circular arc curve. The IVC timing of the Atkinson engine was delayed by a 20° crankshaft angle with respect to standard timing. The compression ratio was increased from 8.5 to 9.5. Tests were conducted at 1400–3400 rpm speed range at WOT. Experiments were conducted at three different operating conditions: Otto cycle for the standard engine, late closing of the intake valve at 20 ° CA at 8.5 compression ratio and late closing of the intake valve at 20 ° CA at 9.5 compression ratio. In the tests, the variation of torque, power, BSFC and thermal efficiency with speed were investigated. The results showed that torque, power, BSFC and thermal efficiency were improved with Atkinson CR9.5 operation compared to the standard Otto cycle operation at high speeds. It was obtained that the torque and power of the Atkinson CR9.5 cycle engine increased by 6.7% and the thermal efficiency increased by 12.8% at 3400 rpm speeds. In addition, BSFC of the Atkinson CR9.5 engine decreased by 12.7%.

在这项研究中，使用进气门延迟关闭和增加压缩比的方法，将奥托循环发动机转换为阿特金森循环发动机。首先，进行了热力学分析。在分析中，考虑了比热随温度，热损失，泵送和机械摩擦损失的变化。获得了缸内压力变化，扭矩，功率，热效率以及特定于制动器的燃油消耗随速度的变化。为了进行实验研究，使用圆弧曲线设计并制造了一种新的凸轮轴。阿特金森发动机的IVC正时相对于标准正时延迟了20°曲轴角。压缩比从8.5增加到9.5。在WOT下以1400-3400 rpm的速度范围进行了测试。实验是在三种不同的工况下进行的：标准发动机的奥托循环，进气门在20°CA下以8.5压缩比延迟关闭和进气门在20°CA下以9.5压缩比延迟关闭。在测试中，研究了扭矩，功率，BSFC和热效率随速度的变化。结果表明，与标准Otto循环高速运行相比，Atkinson CR9.5运行改善了扭矩，功率，BSFC和热效率。结果表明，在3400 rpm的转速下，阿特金森CR9.5循环发动机的扭矩和功率增加了6.7％，热效率提高了12.8％。此外，阿特金森CR9.5发动机的BSFC下降了12.7％。进气阀在8.5压缩比下在20°CA下关闭，进气门在9.5压缩比下在20°CA下关闭。在测试中，研究了扭矩，功率，BSFC和热效率随速度的变化。结果表明，与标准Otto循环高速运行相比，Atkinson CR9.5运行改善了扭矩，功率，BSFC和热效率。结果表明，在3400 rpm的转速下，阿特金森CR9.5循环发动机的扭矩和功率增加了6.7％，热效率提高了12.8％。此外，阿特金森CR9.5发动机的BSFC下降了12.7％。进气阀在8.5压缩比下在20°CA下关闭，进气门在9.5压缩比下在20°CA下关闭。在测试中，研究了扭矩，功率，BSFC和热效率随速度的变化。结果表明，与标准Otto循环高速运行相比，Atkinson CR9.5运行改善了扭矩，功率，BSFC和热效率。结果表明，在3400 rpm的转速下，阿特金森CR9.5循环发动机的扭矩和功率增加了6.7％，热效率提高了12.8％。此外，阿特金森CR9.5发动机的BSFC下降了12.7％。结果表明，与标准Otto循环高速运行相比，Atkinson CR9.5运行改善了扭矩，功率，BSFC和热效率。结果表明，在3400 rpm的转速下，阿特金森CR9.5循环发动机的扭矩和功率增加了6.7％，热效率提高了12.8％。此外，阿特金森CR9.5发动机的BSFC下降了12.7％。结果表明，与标准Otto循环高速运行相比，Atkinson CR9.5运行改善了扭矩，功率，BSFC和热效率。结果表明，在3400 rpm的转速下，阿特金森CR9.5循环发动机的扭矩和功率增加了6.7％，热效率提高了12.8％。此外，阿特金森CR9.5发动机的BSFC下降了12.7％。