Influences of Swirl and Turbulence on the Burning Velocity in an Engine Cylinder : 1st Report, On the HoT-wire Measurement of the Instantaneous Gas Velocity in a Cylinder

Abstract

In order to the unsteady flow problems in engine cylinders, the heat transfer from hot-wires, a length-diameter ratio of which is about 400, has been measured with a constant-temperature anemometer. Gas temperatures and wire temperatures were varied independently of each other from 306 to 351°K respectively. After corrections for the heat conduction to the wire supports and the temperature jump at the wire surface by taking the temperature dependence of the thermal accommodation coefficient into consideration, the continuum Nusselt number can be related to the Reynolds number and the temperature loading factor by the expression N_μm{(Tf/Ta)(300/Ta)}^<0.08 = a+0.68 Re⁰.5_f where the values of gas properties are taken at the film temperature and the value of gas properties are taken at the film temperature and the value of gas properties are taken at the film temperature and the value of a varies between 0.28 and 0.34 for respective wires. The procedures for calculating the gas velocities and temperatures from the relation above and the heat-balance equations for two wires, one of which is operated at the constant-temperature mode and the other at the constant-current mode, are shown also.