最適点火時期の熱力学的解析 : 第3報, 燃焼期間, 熱発生率形状の影響  [in Japanese] Thermodynamical Analysis of Optimum Ignition Timing : 3rd Report, Effects of Combustion Period and Heat Release Diagram  [in Japanese]

The author had previously reported that work done by a power stroke of 4-stroke gasoline engine is expressed as a function of engine factors (ignition timing, combustion period, heat release diagram and so on.) using an approximate pressure diagram of a cylinder, which is an approximate solution of the energy conservation equation. In this report, the author examined the effects of combustion period and heat release diagram on the work done by a power stroke. The results show that (1) the factors mentioned above have little effect on the thermal efficiency at the optimum ignition timing (MBT) ; (2) When combustion period is decreased, MBT shifts from advanced crank angle to retard crank angle in proportion to the decrease of combustion period ; and (3) The idea that a short combustion period improves thermal efficiency does not apply in the case of non-adiabatic engines.