Experimental Investigation of Enhancement Heat Transfer by Natural Convection from Four Finned Cylinders in a Vertical Array Placed in a Conduit
Journal Title: International Journal of Mechanical and Production Engineering Research and Development (IJMPERD ) - Year 2019, Vol 9, Issue 5
Abstract
In this research, experiments have been implemented to enhance heat transfer by free convection from four finned cylinders that have helical fins, fixed horizontally inside conduit and using air as working fluid, the cylinders heated by electrical heaters at constant heat flux (188,341,573,832)W/m2 for Rayleigh number from (5ꓫ104 to 11.5ꓫ104 ) and Prandtl number (0.71)at the ambient temperature, approximately (24–26)oC and pressure at (1 atmosphere). The investigation include designed and manufactured test model, consist from two parts: moving and stationary, the stationary part is a frame made from iron that allows to move the part to inside it, according to ratio(H/D). The ratio (Y/D) changed four times (Y/D=2,4,6,8), the ratio (X/D) changed four times (X/D=1.5,3,5,7) and the ratio (H/D) changed four times (H/D=15,20,25,30). The results showed for all values of heat fluxes, the heat transfer coefficient and Nusselt number increases at separation distances (Y/D=4) & (X/D=3), which gives greater heat transfer rate, and any increasing or reducing lead to reduction in heat transfer rate. But regarding the ratio (H/D), the results showed there was no obvious influence or simple influence on heat transfer. Also, the results showed increased Nusselt number, with increasing Rayleigh number for all cylinders. The experiments have been implemented for single cylinder, placed in free air under constant heat flux, calculated (Nuo) and compared it with (Nui) for cylinders arranged in vertical array at the best case (Y/D=4) & (X/D=3) under the same heat flux (q ͌=341,573,832)W/m2 . The results show, there was obvious enhancement for the cylinders arranged in vertical array compared with singular cylinder in heat transfer, furthermore, this enhancement increases with increasing (Ra). From the results, empirical equation was found, to calculate the value of (Numean) that includes the two variables with (Ramean) as follows: Numean= 0.765Ra0.2 (Y/D) 0.08 (X/D) 0.01 (5ꓫ104≤ Ra ≤ 11.5ꓫ104).
Authors and Affiliations
Dr. Hassan K. Abdullah, Raad Y. Khudair
Keywords
Related Articles
- EP ID EP671647
- DOI 10.24247/ijmperdoct201920
- Views 96
- Downloads 0
An Integration of Smart Grids with Demand Side Management and Renewable Energy: A Review
The scheduling and improvement of the intelligible smart grid (SG) system is a combined part of the revolutionary target of accomplishing the distributed energy generation and transmission. The progression based on the f...
EXPERIMENTAL INVESTIGATION ON MECHANICAL CHARACTERIZATION OF PAN CARBON
The main factors that derive the use of composites are weight reduction, corrosion resistance, specific strength and stiffness, when compared to traditional materials or conventional materials. Characterization of each c...
Air Ambulance Drone - A Modern Conceptual Aerial Vehicle for Surveillance and Casualty Evacuation
The present works discuss the design of an Air Ambulance Drone (AAD), anuncrewed aerial vehicle or UAV has the ability to perform an operation to handle numerous activities like vigilance, saving people, any unpleasant c...
The Design and Fabrication Manually Operated Seed Planter Machine
Agro-Technology is the process of applying the technology innovation occurring in daily life and applying that to the agriculture sector which improves the efficiency of the crop produced and also to develop a better mec...
Peri-Urban Areas: Sustainability Dimension
Peri-urban areas are defined as the areas that surround our metropolitan areas and cities - neither urban nor rural in the conventional sense. They are the fastest growing regions, globally. This paper comprises of vario...