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 85
- Downloads 0
Quantification of Prioritized Requirements of Steel Product with QFD Analysis
It is a customer oriented way to deal with and analyze HOQ implementation focusing on to set up the requirements, priorities, and importance of the design requirements. The customer developed product is found through an...
Thermal and CFD Analysis of Engine Fins for Different Materials with Varying Slot Sizes and Shapes
The engine is the heart of an automobile which is subjected to high temperature variation and thermal stresses. The high temperatures produced in the engine cylinder needs to be reduced for effective working of the engin...
An Investigation of Oxy-Fuel Cutting of Mild Steel using Principle Component Analysis and Taguchi Technique
Oxy fuel cutting process is most widely used in manufacturing and fabrication industries. The properties of the cut pieces are to be studied, in order to have high quality characteristics. In this investigation, mild ste...
Operational Study of Circulating Fluidized Bed Steam Generator
The paper aims at studying the operation of a lignite fired Circulating Fluidized bed Combustion steam generatorof 250 MW capacity located at NeyveliinTamilnadu in South India. Circulating fluidized bed combustion(CFBC)...
FRICTION STIR PROCESSED AA6061 WITH B4C – GRAPHITE HYBRID SURFACE COMPOSITE AND ITS MECHANICAL BEHAVIOUR
In this study, A6061-B4C-Graphite hybrid surface composites were fabricated with different volume percentages using micron sized particles via friction stir processing technique in order to increase the surface mechanica...