Browsing by Author "CHANG, TS"

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DEVELOPMENT OF OSCILLATORY ASYMMETRIC RECIRCULATING FLOW IN TRANSIENT LAMINAR OPPOSING MIXED CONVECTION IN A SYMMETRICALLY HEATED VERTICAL CHANNEL
(1993-05-01)
LIN, TF
;
CHANG, TS
;
CHEN, YF
;
交大名義發表
;
機械工程學系
Detailed flow and thermal characteristics in transient laminar opposing mixed convection in a vertical plane channel subject to a symmetric heat input are numerically investigated. First, a linear stability analysis was employed to evidence the occurrence of flow bifurcation. Then, the unsteady Navier-Stokes equations along with the continuity and energy equations were respectively integrated by a third-order upwind and power-law finite-difference scheme with the resulting matrices inverted by the Fast Fourier Transform and conjugated gradient methods. Reverse flow in the form of symmetric, elongated recirculating cells is initiated earlier and is stronger in a lower Prandtl number fluid with higher opposing buoyancy and Reynolds number and longer heated section length. A t a high opposing buoyancy, sudden flow asymmetry and oscillation occur simultaneously in a nearly steady flow after the initial transient. Periodic flow and thermal evolution are noted in space and time. An empirical equation for the condition for inducing flow oscillation is proposed.
ON THE REVERSED FLOW AND OSCILLATING WAKE IN AN ASYMMETRICALLY HEATED CHANNEL
(1990-03-01)
CHANG, TS
;
LIN, TF
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
ROUTH-HURWITZ CRITERION
(1974-01-01)
CHANG, TS
;
CHEN, CT
;
工學院
;
College of Engineering
STEADY AND OSCILLATORY OPPOSING MIXED CONVECTION IN A SYMMETRICALLY HEATED VERTICAL CHANNEL WITH A LOW-PRANDTL NUMBER FLUID
(1993-10-01)
CHANG, TS
;
LIN, TF
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
Steady laminar and transient oscillatory mixed convection of a low Prandtl number fluid in a symmetrically heated vertical plane channel subject to an opposing buoyancy is investigated by solving the transient two-dimensional flow and energy equations. Results are particularly presented to illustrate the effects of buoyancy strength Gr/Re2 and Reynolds number Re. At a fixed Reynolds number, the flow is steady and unidirectional for a long time for a very small Gr/Re2. At a higher Gr/Re2, steady flow reversal is noted. An oscillatory flow with a single fundamental frequency is found when Gr/Re2 exceeds a critical value (which is about - 1.2 with Re = 500). Flow asymmetry appears at a certain time instant. Further increasing the opposing buoyancy, a secondary fundamental frequency sets in and the flow is quasi-periodic. The effect of increasing the Reynolds number is to stabilize the flow. Besides, in the initial transient the larger Reynolds number results in a longer duration in which a number of symmetric cells oscillate longitudinally. Finally, the transition of various flow patterns can be clearly distinguished by noting a sudden change of the average Nusselt numbers.
TRANSIENT BINARY MIXTURE NATURAL-CONVECTION IN SQUARE ENCLOSURES
(1990-02-01)
LIN, TF
;
HUANG, CC
;
CHANG, TS
;
交大名義發表
;
機械工程學系
TRANSIENT BUOYANCY-INDUCED FLOW THROUGH A HEATED, VERTICAL CHANNEL OF FINITE HEIGHT
(1989)
CHANG, TS
;
LIN, TF
;
機械工程學系
;
Department of Mechanical Engineering