Numerical studies of the simultaneous development of forced convective laminar flow with heat transfer inside a microtube at a uniform temperature

Abstract

Conjugate heat transfer is a complex problem because heat is transferred from a solid medium to a liquid medium through their interfaces. The steady-state laminar flow formed inside the microtubules is subjected to a constant temperature at the outer sidewall surface. These images cover a wide range of wall-to-fluid thermal conductivity ratios (ksf = 1, 2, 3, 4, and 5) and wall thickness-to-inner diameter ratios (δ/Ri = 0.25, 0.5, 0.75, 1, 1.25, and 1.5) and Reynolds numbers (Re = 200, 400, 600, 800, and 1,000). The results are processed by a Fluent program based on the finite volume method to numerically integrate the driver’s differential equations. The results show that increasing the wall-to-fluid thermal conductivity ratio ksf increases the inner wall dimensionless temperature and decreases the average Nusselt number. Conversely, an increase in the ratio of wall thickness to inner diameter results in a decrease in the dimensionless temperature of the inner wall and an increase in the average Nusselt number.

Keywords

• conjugate
• enhancement of heat transfer
• force convection
• microtube
• simultaneous