抄録
Numerical flow simulation is effective in decreasing the cost and time required for swirl port development of a direct-injection diesel engine. There is a certain problem, however, in predicting paddle wheel rotation speed of a swirl tester by means of numerical flow simulation results. This paper proposes a new model for predicting the paddle wheel rotation speed based on fluid force. The prediction results for the paddle rotation speed using this model show better agreement with experimental results than the conventional momentum model. Moreover, a characteristic of the paddle wheel rotation was analyzed using this new prediction model. The result indicates that paddle wheel rotation speed is strongly influenced by the swirl velocity profile inside a cylinder in case of the same angular momentum field.