Temperature Measurement of Flame in a Gasoline Engine : 1st Report, Measurement of Average Temperature

One method to measure the instantaneous flame temperature within the cylinder of a gasoline engine by means of the absolute radiation method is proposed. The radiation energy of D-line emitted from a trace of sodium, which is added to fuel, is measured by an optical-electronic system. Then, the measured energy is converted into the equivalent black body temperature. This temperature may be considered as the flame temperature which is averaged through an optical path in the luminous flame zone. In the process of conversion, the half-width of D-line is determined experimentally and the number of Na atoms radiating in the optical path is evaluated theoretically. As the optical system, a quartz window, 4 limiting diaphragms, an interference filter and a fiber-scope are arranged in order. And a light beam having 1 mm in diameter is introduced to a photo-multiplier by means of the fiberscope. By this technique, the flame temperature in CFR engine is measured under various operating conditions.