Study on the Drag of a Cylinder and a Sphere with Flames Supported in Air Stream

抄録

This paper is mainly concerned with explaining the mechanism of the reduction in drag of a burning fuel droplet. The research was carried out with the following results : Cylinder with a flame : (1) The drag of such a cylinder with a wake flame is about 0.8 times as small as that of a similar cylinder without a flame, and it varies proportionally to the square of the velocity of the air stream. (2) The reduction in drag measured directly is in fairly good agreement with that calculated according to the momentum theory. (3) In the range 1300<R_e<5000, this cylinder with a flame makes noise. This noise arises from the vibration of the flame. Sphere with a flame : The variations of drag with R_e are qualitatively the same as in the case of the cylinder. The drag of such a sphere with a flame is about 0.7 times as small as that of a similar sphere without a flame.