## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Thermal radiation mixed convection boundary layer flow in tightly coiled curved pipe for large Richardson number

**ABSTRACT**

The characteristics of radiative mixed convection boundary layer flow generated close to the inner walls of tightly coiled curved pipe for full range of Richardson number λ is investigated. In order to find numerical solutions the governing coupled, nonlinear partial differential equations are transformed into convenient form for integration by using Primitive Variable Formulation. From this transformation the terms highest powers of Dean Number (D=δ1/2Re)are retained into boundary layer form and then solved numerically by using Finite Difference Method. Expressions for the axial and transverse components of skin friction, heat transfer coefficient and flux thicknesses for various values of Richardson Number λ, angle α, curvature of the pipe (tightly coiled pipe in which 0<δ<1), Plank Number Rd and Prandtl Number Pr are obtained and given graphically.

**KEYWORDS**

PAPER SUBMITTED: 2015-08-05

PAPER REVISED: 2016-05-17

PAPER ACCEPTED: 2016-05-17

PUBLISHED ONLINE: 2016-05-30

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