Based on the attitude of science discovery, an industrial induction motor silencer is designed and developed, and the performance of this silencer is evaluated experimentally in this paper. The basic principle of the silencer was used as the parabola principle. During the experiment, the performance of the proposed silencer is preliminary researched using software simulation method, test analogy method, and some other methods to infer experiment was conducted to evaluate the experiment. During the simulation experiment, 25dB level can be reduced in the 12,500∼16,000Hz range. More than 35dB level was reduced in the 2,500∼5,000Hz range. When we used the silencer, the noise in the high frequency bands above 1,000Hz are reduced. In particular, 1,600Hz band is greatly reduced on average by 5dB. Some effective conclusions are obtained from the analysis of the experiment results, despite some uncertain factors in the experiment

Diesel particulate matter is one of the major harmful emissions under strict regulations. The exhaust after-treatment devices are added to the diesel engines as stricter regulations are introduced worldwide. In the present study, new system of smoke reduction of diesel engine is proposed. This new system is using suction equipment and fiber glass filter included moisture for capture smoke. For verification of new system experiments are performed at diesel engine. As a result it is founded that smoke is decreased.

Sucking spray type liquid dispenser does to ply piston by exclusive use cylinder, did so that dispenser may can do pumping, and control sucking and interception of dispenser by sucking piston and interception node in main cylinder interior and control coating emperor's the spray amount more minutely in main cylinder, various coating emperors of low viscosity so that fixed quantity spray is possible spray type liquid dispenser be. In this paper, spray angle and theoretically cover extent in actuality cover extent is difference, spray form, spray air, spray high, over lap extent according to use usage becomes different and actuality cover extent applies over lap 20[%], and succeed to reduce error of cover extent maximum theoretically with actuality cover extent and got near result in cover extent of 10[%] withins.