| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥3,000,000 (Direct Cost: ¥3,000,000)
|
|---|
| Research Abstract |
Knock phenomenon was found affected by Negative Temperature Coefficient(NTC), examined by experiments using a constant volume chamber. However, as the conditions such as pressure, fuel, unsteadiness, temperature and turbulence are quite different from production engines, a rapid compression machine, which can simulate the conditions in actual engines, was designed and built. As this machine is based on a machine developed at Kyusyu Univ., it has features such as compact, variable piston-motion profile, moderate vibration. Using this machine, measurements of gas temperature and pressure, visualization, and gas analysis can be achieved. Because the local gas temperature measurement is considered as the most important factor for knock, it was made by using two-wired thermocouples, allowable the measurement even in the vicinity of wall As a result, although the accuracy depends on the flow direction, density, and velocity, measurement was made within 2% error. Meanwhile, 0-dimensional numerical analyses were carried out for data taken with the constant volume chamber. Through this study, useful information for knock analysis was obtained, especially conditions whether knock occurs or not. NTC was found affective, depending on experimental conditions. To avoid knock, reductions in the gas temperature, the duration in high temperature and unbumed fuel at the moment of knock initiation are affective.
|
