Transient heat transfer from a wire in a violently fluctuating environment

Abstract

A closed form perturbation solution is obtained for the problem of transient heat transfer from a constant temperature circular cylinder in a violently fluctuating flow of incompressible Newtonian fluids. The small parameter used in the solution is the ratio of the maximum fluctuation amplitude to the cylinder diameter. The solution is asymptotically valid for any values of the Prandtl and Reynolds numbers. The natural convection is considered as the second-order effect. The solution is also applied to predict the initial transient heat transfer from a wire which starts from rest an arbitrary translational motion. Numerical results in terms of time-dependent local and average Nusselt numbers are used to demonstrate the significant time lag of heat transfer response to the fluctuating velocity. It is shown that an optimum frequency of sinusoidal oscillation exists for the maximum net heat transfer at given flow parameters.