Heat Transfer From Normally Impinging Flames

Abstract

An investigation is described relating to the prediction of rates of convective heating from normally impinging hydrocarbon oxygen flames to a plane surface. A transient calorimeter was employed to measure the heat transfer and the technique incorporated a means for the determination of heat losses. The theoretical approach was based on the modification of a semi- empirical heat transfer equation. A comparison of the experimental and theoretical results showed that for several of the flames studied large experimental over-estimates or under-estimates of the calculated equilibrium flow heat transfer values were obtained depending upon the extent of mixing induced turbulence at the plane of impingement in the free firing flame and the proximity of the impinged surface to the primary flame cones. It was postulated that the inhibition of heat transfer rates by mixing induced turbulence was dependent upon the radius of curvature of the impinged surface.