The Effect of Multi-size Valve on Improvement of Swirl Flow for Gas-based EF7 Engine

Antioxidants One of the methods to increase the combustion efficiency in an internal combustion engine is to create swirl flow. In EF7 engine, there are two inlet valves per cylinder so small amount of swirl flow may be created. Most of the conventional methods for generating vortex current, even used in new engines, require major design and modifications of cylinder head, and their costs are significant. In this study, a new low-cost method was developed to create vortex flow. The goal of the changes is to develop inlet flow difference between the two inlet valves led to develop swirl flow in the cylinder in order to increase the combustion efficiency provided that the flow coefficient doesn’t face a loss. First, the swirl flow in an EF7 engine was measured at steady state and then the intended changes was implemented on the two ends of the cylinder head. After that, all valves sits' angle were fabricated in accordance with corresponding standards. Then, this method was experimentally evaluated using the flow bench test so that in addition to measure the accuracy of swirl flow, the swirl flow coefficient can be compared with other methods such as flow control valve. The results show that there is a minor reduction in flow coefficient for low valve lifts, but It can be gained an acceptable amount of swirl flow for high valve lifts with minor costs and changes for cylinder head in comparison with other designs.