Abstract This paper reports on the determination of the flame height of a flare system using theoretical approach based on the laws of conservation of mass, momentum and energy. The set of ordinary differential equations at steady state conditions are solved numerically by fourth order Runge-Kutta method. The extent of reaction between the fuel and the entrained air has been studied by introducing the reaction mixing efficiency parameter, as the reaction rate is fixed by local entrainment rate. The reaction mixing efficiency parameter is a key measure to determine the height of the flame and its variation with the source velocity is limited by the flame width and the maximum vertical flame velocity at the tip of the flaming region. The variation of different parameters as vertical flame velocity, flame geometry and flame temperature with flame height are shown in plots. It is found that the flame geometry undergoes an initial necking up to a certain height, followed by an increase in its spread thereafter. The flame geometry and the flame dynamics depend exclusively on the burner design and the stack exit velocity. The flame height to burner diameter ratio of the jet diffusion flame is found to vary linearly with Froude number with a constant slope in the logarithmic plot.

ABSTRACT The present study was carried out to investigate the effect of dietary supplementation with vitamin E and stocking density on the mortality, body weight gain, feed conversion ratio, European production efficiency factor, heterophil/lymphocyte (H/L) ratio and liver glutathione (GSH) and malondialdehyde (MDA) levels of broilers. In total, 570 one-day-old Vencobb 400 broiler chickens were randomly assigned to three treatments, with six replicates each. G1 served as normal control and birds were provided a normal floor space (0.0465 m2/bird from day 1 to 21 and 0.0929 m2/bird from day 22 to 42) and basal diet containing vitamin E at 70 g/ton feed (n=150). G2 and G3 birds were subjected to high stocking density (0.0279 m2/bird from day 1 to 21 and 0.0557 m2/bird from day 22 to 42). G2 served as the high stocking density (HSD) control, birds were offered a basal diet with no vitamin E (n=210), whereas G3 birds were fed a basal diet containing vitamin E at 70 g/ton feed (n=210). The birds were fed with feed and water ad libitum throughout the study period. The supplementation of vitamin E to the birds subjected to HSD had a positive effect on body weight gain, feed conversion ratio (FCR), European Production Efficiency Factor (EPEF), H/L ratio, and liver GSH and MDA levels with those subjected to HSD and not supplemented with vitamin E. The results of the present study indicate that the supplementation of vitamin E at 70g/ton of feed to broilers subjected to HSD could effectively reverse the negative effects of HSD, and improve broiler performance.