Convective Heat Transfer and Flow Resistance Characteristics of Various Types of Elliptical Tubes

Convective heat transfer and flow resistance characteristic around elliptical tubes with different axis radio K in cross flow are investigated in this paper. Eight types of elliptical tubes have been calculated using numerical method. The local and overall convective heat transfer coefficients and flow resistance coefficients are obtained with the Reynolds number ranging from 4000 to 80000. And the relationship of convective heat transfer and flow resistance with Reynolds and K is analyzed. At last, four types of elliptical tubes´ local convective heat transfer characteristics are showed. The results show that the experimental data are found in good agreement with the calculated results by the type of K = 2. Nusselt number is increasing and Euler number is decreasing with the increase of Re .It is found the local convective heat transfer coefficients vary with K, and the separation of the boundary layer shifts downstream with the increase of K.