Injection rate, injection quantity and injection timing of fuel are controlled precisely by electric control in CRDI system.Particularly, injection rate being influenced with injection pressure affects to spray characteristics and fuel-air ratio, so it is a very important factor in diesel combustion. In this study, injection rates in accordance with injection pressure at a constant ambient pressure were measured with Zeuch's method. Under the same condition, non-evaporating spray images were taken with a high speed camera and analyzed carefully with Adobe Photoshop CS3. Macroscopic spray characteristics and breakup processes in the spray could be found from the examined and analyzed data. Injection start time and injection period were practically affected with injection pressure. Also, initial injection rate, spray penetration, spray angle and breakup of high density droplets region in the spray were affected with injection pressure. The results and techniques of spray visualization and injection rate measurement in this study would be practically effective to study a high pressure diesel spray for common rail direct injection system.

This paper is an experimental study to investigate utility of ultrasonic treatment of fuel oil in diesel engine. Experiment was carrid out to clarify the effect of ultrsonic vibration on the characteristics of maximum pressure, fuel consumption ratio, smoke, BMEP and torque. The result obtained are as follows: 1. In the case of given ultrsonic vibration, the maximum pressure is increased in all experimental conditions. 2. In the case of given ultrsonic vibration, the decrease effect of fuel consumption rate is increased at low rpm. 3. The generation quantity of soots is increased according to load. In the case of given ultrsonic vibration, the decreased quantity of soots does not very according to load. 4. In the case of given ultrsonic vibration, the BMEP and torque are increased at low load.

In this paper, the relationship between static pressure recovery and turbulent energy was presented in case of swirling flows into a conical diffuser. The distributions of turbulent energy in a diffuser sectional area were measured by a hot wire anemometer. The following conclusion can be drawn from the experiment. Diffuser loss is constituted by a dynamic pressure loss and total pressure loss. The static pressure recovery depends strongly on the total pressure loss. The static pressure recovery depends strongly on the total pressure loss, and the turbulent energy varies inversely as the static pressure recovery coefficient.

The purpose of this paper is to investigate the relationship between static pressure recovery and velocity distributions in case of swirling flow into a conical diffuser. In this research, velocity distribution is measured by a multi-hole yaw-meter. The following conclusions can be drawn from the experiments. (1) The static pressure recovery depends strongly on the strength of a swirl. (2) A high pressure recovery coefficient is achieved by inserting a solid core into the diffuser center.

가변 압축비 기관(C. F. R.)에 ionization gap probe를 피스톤 및 실린터 헤드 sleeve에 설치하여 화염거동에 대하여 실험한 결과는 다음과 같다. 1) 혼합연료에서 화염전파속도는 메타놀 함량에 따라 증가한다. 2) 혼합연료에서 메타놀 percent가 증가하면 에너지 소모비 (Btu/HP-hr)가 감소하여 열효율은 증가한다. 3) 당량비가 일정하면 평균유효압력은 메타놀 량이 증가할수록 감소한다. 4) 순수한 가솔린 및 혼합연료는 점화진각이 클수록 NO 하(X) 방출량은 증가하고 희박 혼합기 영역에서 NO 하(X) 방출량은 최대가 된다. 또 RG50/M40/THF10/W1의 연료에서는 당량비가 0.95이하에서는 당양비가 낮을수록, 점화진각이 높을수록 NO 하(X) 방출량은 증가하고, 0.95 이상에서는 당량비와 점화진각이 클수록 방출량은 감소한다. 5) CO, HC의 최소값은 메타놀 함유량이 높을수록 감소한다.