Numerical Study Of Heat Transfer Characteristics In Divergent Ribbed Square Channels

Ribbed channel cooling is widely used in turbine blade internal passage cooling and other fields.Such as solar air heaters,heat exchangers,etc.In order to reduce the temperature of the turbine blades and maintain normal operation,this paper uses the cooling channels inside the gas turbine blades as a background.Numerical simulation methods are used to study the heat transfer characteristics of 7 different types of fins in the diverging square channel;The secondary flow intensity explored the heat transfer mechanism,and obtained the following results:(1)For the gradually expanding ribbed square channel,the rib height,inclination angle,open-area ratio and depth of attack angle affect its heat transfer performance.(2)For a divergent square channel with straight ribs,the heat transfer performance increases with the increase of the rib height e,and the secondary flow strength Se increases with the increase of the rib height e and the rib spacing p.The comprehensive heat transfer factor JF is the largest when p=40mm and e/Dm=0.08,indicating that the comprehensive heat transfer effect is the best at this time.(3)For the divergent square channel with inclined ribs,the heat transfer effect ofα=45°rib is the best and Se is the largest,while the comprehensive heat transfer factor JF isα=30°,p=40mm and p=50mm is the largest,indicating the best comprehensive heat exchange effect at this time.(4)For the gradually expanding square channel with slit ribs,the heat transfer effect ofβ=0.1 ribs is the best and Ses is the largest,and the comprehensive heat transfer factor JF is the largest when p=40mm and β=0.3,indicating that this time The comprehensive heat exchange effect is the best.(5)For the divergent square channel with V ribs,the heat transfer performance and secondary flow strength Se increase with the increase of rib height e,the heat transfer effect ofθ=45°rib is the best,θ=30° rib has the largest Se.(6)For the divergent square channel with W ribs,the heat transfer performance and secondary flow strength Se increase with the increase of rib height e,the heat transfer effect is the best and Se maximum of θ=30° ribs.(7)For the ribbed divergent square channel,Nu and Se increase with the increase of Rem,and f is almost unchanged with the increase of Rem.(8)Nu increases with the increase of Se,and there is a one-to-one correspondence between the longitudinal vortex intensities Se and Nu in the seven kinds of ribbed divergent channels.(9)For the comprehensive heat transfer of the gradually expanding ribs and square channels,the V-up rib has the best comprehensive heat transfer effect,and the W-down rib has the worst comprehensive heat transfer effect;the other ribs take the second place.