Computational investigation of heat transfer from an oscillating cylinder.

The problem of convective heat transfer from an oscillating cylinder is investigated numerically. An isothermal cylinder was forced to oscillate in the in-line and transverse directions at the mid-point lock-in frequencies with different position amplitudes of oscillation. The governing equations in a non-inertial frame of reference are simplified to obtain the vorticity, stream function and energy equations. After applying the log-polar coordinate transformation, the non-dimensional vorticity and energy equations, with appropriate boundary conditions, were solved using an alternating direction implicit method. The Poisson equation for stream function was solved iteratively using the successive over relaxation technique. The time dependent average Nusselt number and the local Nusselt number distribution on the cylinder surface were computed at a Reynolds number of 200 with the cylinder oscillating in the in-line direction, transverse direction and combined in-line and transverse directions with position amplitudes ranging from 0.1 diameter to 0.8 diameter. The dominant frequency in the average Nusselt number variation was found to be twice the natural shedding frequency. The location of the maximum local Nusselt number depends on the direction and the velocity amplitude of oscillation. With both forced and mixed convection, the local Nusselt number distribution approximately repeats after one cycle of oscillation. In comparison with the heat transfer from a stationary cylinder, an increased mean Nusselt number and amplitude of the average Nusselt number variation were predicted with the in-line, transverse and combined oscillation. A maximum increase of 18.46% in the mean Nusselt number was predicted when the position amplitude of oscillation was 0.2 diameter in the in-line direction and 0.8 diameter in the transverse direction. Two cases of oscillating hot-wire responses were also computationally predicted in terms of average Nusselt number. The time history of the average Nusselt number agrees qualitatively with the oscillating hot-wire output voltage response.Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1995 .K36. Source: Dissertation Abstracts International, Volume: 57-07, Section: B, page: 4658. Thesis (Ph.D.)--University of Windsor (Canada), 1995