COMBINED FREE AND FORCED LAMINAR CONVECTION IN TRIANGULAR DUCTS

抄録

A numerical method using the finite difference techniques for a triangular coordinates system is presented for flow and heat transfer problems of fully developed combined free and forced laminar convection in arbitrary triangular ducts, where the boundary condition with the axially uniform wall heat flux and the peripherally uniform wall temperature is taken into consideration.
The numerical examples are carried out for horizontal isosceles and inclined equilateral triangular ducts. For the horizontal isosceles triangular ducts, correlative relationships with respect to fRe/(fRe)₀ vs. ReRaPr and Nu/Nu₀ vs. ReRaPr at Pr=0.73 are obtained for various vertex angles, where subscript 0 signifies the value of pure forced convection. Additionally, the influence of those relationships by Pr is examined.
For inclined equilateral ducts with upward flow, fRe and Nu are correlated with the two modified parameters, Ra^* and Re^*, implicitly including an inclination angle. Furthermore, the influence of rotation and inclination angles on fRe and Nu is shown for equilateral triangular ducts.