| Abstract:In order to simulate the effects of ignition timing, speed, and release valve operating parameters on engine combustion brake performance, the GT-Power software was used to establish a model of a certain engine and the simulation was then conducted. The results show that the engine braking power increases linearly with the advance of the ignition timing. At each ignition timing, the higher the engine speed, the greater the braking power; the higher the release valve lift, the greater the braking power. When the engine speed remains constant, each release valve lift has an optimal valve advance angle where the braking power reaches peak, and the optimal valve advance angle decreases as the release valve lift increases. When the release valve lift is fixed, each engine speed has an optimal release valve advance angle where the braking power is the maximum, and the optimal valve advance angle increases with the engine speed. At 4 mm valve lift and 2400 r/min engine speed, the maximum braking power is 137 kW, 1.7 times the rated engine power. |