EXPRIMENTAL STUDY ON EFFECTS OF A SINGLE POROUS-TYPE ROUGHNESS ELEMENT IN A PARALLEL-PLATE DUCT
- 1 October 1991
- journal article
- research article
- Published by Taylor & Francis Ltd in Experimental Heat Transfer
- Vol. 4 (4), 319-330
- https://doi.org/10.1080/08916159108946424
Abstract
Experiments were carried out to examine the effects of a single porous-type roughness element on the insulated wall opposite the smooth heated plate on the heat transfer. The local heat transfer and drag coefficients depend on the porous diameter and the porosity. The local heat transfer coefficient takes a peak, PI, under the porous element in laminar flow. On the other hand, in turbulent flow, it takes two peaks, PI and P2, under and after the element, respectively. The position of peak P2 varies with the height of the element and the Reynolds number. The drag coefficient of the porous element is lower than that of the solid element. According to thermal performance at constant pumping power, this kind of element should be used in laminar flow. In addition, it is estimated that the porous element should be utilized in the composite effects (the turbulence increase and the thermal radiation shielding effect) of heat transfer in order to apply the element effectively.Keywords
This publication has 7 references indexed in Scilit:
- Effects of Several Roughness Elements on an Insulated Wall for Heat Transfer From the Opposite Smooth Heated Surface in a Parallel Plate DuctJournal of Heat Transfer, 1987
- EFFECTIVE ENERGY CONVERSION METHOD BETWEEN GAS ENTHALPY AND THERMAL RADIATION AND APPLICATION TO INDUSTRIAL FURNACESPublished by Begell House ,1982
- Heat transfer in a layered porous medium heated from belowJournal of Fluid Mechanics, 1981
- Film Boiling in a Scaling LiquidJournal of Heat Transfer, 1976
- PERFORMANCE EVALUATION CRITERIA FOR ENHANCED HEAT TRANSFER SURFACESPublished by Begell House ,1974
- Heat transfer and friction in tubes with repeated-rib roughnessInternational Journal of Heat and Mass Transfer, 1971
- Friction and Heat Transfer Characteristics in Turbulent Swirl Flow Subjected to Large Transverse Temperature GradientsJournal of Heat Transfer, 1968