A single, semi-empirical, correlation equation for laminar forced convection heat and mass transfer from isopotential spheroids is presented. It is based on blending Pec Peclet number [Ret Pr] two correlation equations of Yuge developed for isothermal spheres in air streams, and the diffusive body length, square root of the total body surface area, of Yovanovich recently proposed for laminar natural convection from complex bodies. The proposed correlation equation is in very good to excellent agreement over the full range of the Reynolds number 0 <_ Rec 5 lo6 with several other correlation equations developed for spheres and spheroids, s shape factor but over limited ranges of the Reynolds number. 5 P P r 6 Q Q; Rec I S C Schmidt number [./Dl Shc Nomenclature T temperature of extensive fluid To uniform body temperature dimensionless outward 'body normal [n/C] maximum (equatorial) body perimeter Prandtl number [ . / a i dimensionless pressure heat Bow rate dimensionless heat flow rate [QC/A(To -Tm)kl Reynolds number [ U m L / v ] spherical coordinate Sherwood number [She = h,L/D] U A surface area of the body [Cad] T, Buid temperature remote from the body Cartesian coordinates J;i diffusive characteristic body length of % Y , Z A l p Yovanovich UW uniform free stream velocity Pasternak-Gauvin characteristic body length 9 dimensionless surface area [AIL'] -AR aspect ratio of oblate and prolate spheroids velocity vector A a sphere radius 26 spheroid equatorial diameter [ P / r ]C , , C t , C a correlation coefficients C concentration in the extensive fluid Greek Letters eo uniform body concentration a thermal diffusivity of the extensive fluid Cm concentration remote from body a1 Drake-Backer parameter [Jm] D sphere diameter 11 dummy variable in Eq. (17) D molecular d i h i v i t y 9 spherical coordinate e eccentricity of spheroids P*,Pm fluid viscosity at surface and free stream h heat transfer coefficient temperatures h, mass transfer coefficient U kinematic viscosity of the extensive fluid z unit vector along flow direction P mass density of the extensive fluid k thermal conductivity of the extensive fluid 4 C arbitrary characteristic body length m mass flaw rate V del operator dimensionless velocity vector [V/Um] Bessel function of second kind of order one Yd.1 Bessel function of first kind of order one pm density of fluid remote from the body dimensionless temperature or concentration potential [ ( T -Tm)/(To -T,)] JI(.) m Reynolds number correlation parameter or [(c -cm)/(co -Cm)l dimensionless mass flow rate 9 dimensionless del operator [ L VI [hC/A(co -cm)DI VZ Laplacian operator N u c Nusselt number [ N u t = hC/kl ea dimensionless Laplacian operator [ L'2Q2\ n Prandlt number correlation parameter; W outward body normal 'Professor, Associate Fellow AIAA 'copyright @M.M. Yovanovich 1 Downloaded by KUNGLIGA TEKNISKA HOGSKOLEN KTH on July 30, 2015 | http://arc.aiaa.org |