Predictions of the heat release rate model of hydraulic-free piston engines

Hydraulic-free piston engine are associated with the challenges of large cyclic variations and poor running stability due to the piston free states. It is therefore necessary to investigate the cyclic stability of this engines. For this purpose, the heat release rate was fitted with the double Wiebe function. The error transfer calculation is carried out for the Wiebe characteristic parameters. Then, some cylinder pressures and scavenging duration affecting the engine cycle are selected as detection parameters after cyclic volatility analysis. Finally, the relationship between the characteristic parameters and the detection parameters was then subjected to training on the basis of the training samples that were used to predict the heat release rate by the method of support vector machine. This method will help establish the interrelationship between the parameters of the cycle and establish a foundation for investigating the cyclic stability of HFPE and formulating relevant instability control strategies.