射流间距对多股射流冲击夹套传热的影响OA

A multi-jet impingement jacket tailored for highly exothermic reactions was proposed to intensify heat transfer.Numerical simulations were employed to examine how the axial spacing between successive jet tubes(l)and the jet velocity(v)affected the jacket's thermal performance.The results show that compared with a conventional cylindrical jacket of the same size,the multi-jet impingement jacket markedly raises the area-averaged Nusselt number(Num)on the heat-transfer wall and cuts the pressure drop(Δp).The axial distribution of the local Nusselt number(Nua)exhibits a wavy pattern,with peaks and troughs coinciding with the impingement locations.Over the velocity range 1～4 m/s,varying l has a negligible effect on Δp,whereas v is the dominant factor,and Δp increases monotonically with v.A comprehensive analysis shows that,when the l is 7.5d,the jacket delivers the best wall-temperature uniformity(UNu)and the highest Num among all multi-jet impingement jackets.