Mass and heat transfer from a sphere in a laminar flow

✍ Scribed by Yu.P. Gupalo; Yu.S. Ryazantsev

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 507 KB
• Volume: 27
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(72)80141-6

✦ Synopsis

Abslract-An approximate solution of a steady-state problem of mass and heat transfer from a moving solid sphere at small finite P&let and Reynolds numbers is obtained. The case of a first-order chemical reaction on the sphere surface is considered. The problem is solved by means of matching inner and outer asymptotic expansions in terms of the P&let number, whereas the Schmidt or Prandtl number enters as a parameter. The concentration or temperature field and the total mass and heat flux are obtained. The total mass flow to the sphere surface is found in the form: Sh = q+fqe(Pe+Pe21n Pe+3qPe31n Pe) +4$Q(q,Sc)PeZ+O(PeS) where Sh = PaiD, Pe = ReSc, Re = Ul,alv, SC = vlD, Q(q,Sc) =k-#?+lny-&(2-q)-1+fS~P-fS~-f(S~+ l)*(Sc-2) In (1 +&-I) and q = k/(k+ I), k being the nondimensional reaction rate constant. For the case of heat transfer from an isothermal sphere the above formula is to be modified simply by replacing Sh-number by Nu-number, &-number by Pr-number and putting q = 1 and Pe = RePr.