FLOW PATTERNS OF MIXED CONVECTION IN A HORIZONTAL SQUARE CHANNEL FLOW

Autor: I. G. Lu, K. H. Hou, C. F. Hsu, L. W. Wang
Rok vydání: 1996
Předmět:
Zdroj: Experimental Heat Transfer. 9:257-265
ISSN: 1521-0480
0891-6152
DOI: 10.1080/08916159608946524
Popis: An experimental study of mixed-convection heat transfer flow of a CuSO4 + H2SO4 + H2O solution in a horizontal channel was performed. Unstable temperature gradients imposed by a heated bottom initiated an ascending (secondary) flow of light boundary layer fluid into the free stream. The shadowgraph technique was used to visualize the flow and to determine the nature and effect of thermally driven secondary flows in a horizontal channel with heated top and bottom surfaces and insulated side walls. The ranges of the parameters studied in the present work for the square channel are Pr = 5–7, Re = 100–1,000, and Grqb = 2·8 × 106−2·5 × 107. Flow visualization revealed Ike existence of four regimes corresponding to laminar forced convection, laminar mixed convection, transitional mixed convection, and turbulent free convection. Also, the onset of secondary flow was found to be delayed by decreasing the Grash of number and / or by increasing the Reynolds number. A direction for future study of mixed thermosoluta...
Databáze: OpenAIRE