乱流予混合火炎の火炎片の速度ベクトルに関する一考察  [in Japanese] A Consideration on a Flamelet Velocity-Vector in Turbulent Premixed Flames  [in Japanese]

According to the Huygens' principle for a wave-front propagation, any point on a wave front may be regarded as the source of secondary waves and the surface that is tangent to the secondary waves can be used to determine the future position of the wave front. Therefore, the flamelet velocity-vector is denned as a vector perpendicular to it. However, it seems that this definition is not well understood. In the present paper, the definition of velocity-vector of the wave front is discussed. There is a difference between the particle velocity and the front velocity. The particle velocity, in general, has a component parallel to the front. The front velocity, by definition, is normal to the front. For fronts that propagate from particle to particle, it is impossible to introduce a unique definition of front velocity that has a component parallel to the front. It has been shown that the flamelet velocity-vector is the sum of the burning velocity-vector of the flamelet and the component of the gas velocity-vector parallel to the flamelet velocity-vector.