The Research Of Using Virtual Instrument In Engine Experiment

Engine experiments are a necessary step in engine-producing and engine-researching. With the development of science and technology, the disadvantages of traditional testing instruments have appeared. The development of computers and electronic technology promoted the advancement of virtual instruments. Now, testing instruments have been trending to be flexibile. Customers can build their own testing system according to their practical conditions. The testing system can be extended, amended and upgraded without changing the hardwares or only changing a little. The whole system is flexible, low wasting and high efficient.In this paper the concept of virtual instruments, the composition of LabVIEW and how they have been applied in cars and engines in our country and in foreign countries were summaried. The researches made by the author using virtual instruments based on the existing equipments are as follows:1. The monitoring and control system of engine testing was created. The system can monitor the real-time temperatures and pressures. Speed characteristic, load characteristic, indicated diagram and oil pressure can be acquired on the system. Besides, the datas of each work condition can be saved. The relative diagram and report can be created automatically. The result can be printed. Furthermore, the speed and the throttle of engine can be controlled on the system.2. The oil pressure diagram and indicated diagram were analyzed with LabVIEW for the first time. Many parameters such as the injection starting time, the injection duration and so on were analyzed. The P- diagram was smoothed. Also, it can be transferred into P-V and lnP-lnV diagram. The indicated and effective parameters can be calculated according to the P- diagram. Furthermore, the heat release rate was computed using LabVIEW for the first time.3. The car muffler module with LabVIEW was set up firstly. The different mufflers can be simulated and how much the sound conresponding to the relative frequency has been eliminated can be got from the module.All of the above modules have been tested many times. The result showed that connecting virtual instruments with engines is feasible and convenient. It can be concluded that virtual instrument has played an important role in the development of engine testing technology by both increasing the development efficiency and reducing the time and cost.