Browsing by Author "YANG, WM"

Now showing 1 - 4 of 4

ANALYSIS OF FLUID-FLOW AND HEAT-TRANSFER IN TWISTED CIRCULAR-SECTOR DUCTS
(1986)
YANG, WM
;
機械工程學系
;
Department of Mechanical Engineering
EFFECT OF MODULATION ON RADIATION-INDUCED INSTABILITY
(1995-01-01)
YANG, WM
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
;
Department of Mechanical Engineering
The instability of a fluid layer induced by modulated irradiation is studied numerically. Based on the Eddington approximation for the equation of transfer, the time-periodic temperature profile of the basic state is solved analytically: A system of linear equations with periodic coefficients describing the behavior of disturbances is obtained by linear stability theory. Using Floquet's theory, the disturbances are expanded by a double series of mixed Fourier and Chebyshev form. An algorithm combining Galerkin and collocation methods is developed and successfully traces the stability boundary between stable and transiently stable states. For the case of a fluid layer heated from below by a modulated temperature, the results show that modulation has a destabilizing effect at low frequencies and a stabilizing effect at high frequencies, which is in agreement with the available theoretical analyses and experimental data. The effects of Blot number and radiative parameters, such as Planck number and optical thickness, on the critical Rayleigh number are analyzed and compared with the unmodulated cases.
INSTABILITY OF RADIATION-INDUCED FLOW IN AN INCLINED SLOT
(1993-08-01)
YANG, WM
;
LEU, MC
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
The instability of radiation-induced flow of a participating fluid in an inclined slender slot irradiated from one boundary is studied numerically for the inclination from 0-degrees to 90-degrees. The Eddington approximation is employed for the equation of transfer, and the pseudospectral method is used to solve the linearized perturbed equations. At an angle smaller than the transition angle the instability sets in as stationary longitudinal rolls. At an angle greater than the transition angle the instability occurs in the form of travelling transverse waves. The transition angle for the fluid of Pr = 0.71 is found to be minimum at the optical thickness near unity. Increasing optical thickness decreases the penetration of radiant energy, consequently increases the stability. The critical Rayleigh number increases rapidly with increasing the optical thickness as the optical thickness is greater than one.
THERMAL-INSTABILITY OF A FLUID LAYER INDUCED BY RADIATION
(1990-04-01)
YANG, WM
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
;
Department of Mechanical Engineering