| Description |
viii, 56 leaves : illustrations, photographs ; 29 cm |
| Summary |
"Considerable work has been done in recent years, and is still being done, to find ways of increasing the heat transfer rate in fluid heat exchangers. One particular type of potential heat exchanger that has been studied analytically, as well as experimentally, is the use of artificially roughened tubing. The test sections used in this experiment consisted of four aluminum pipes, three of which have been artificially roughened internally by machining ninety- degree V-shape grooves along the axis of the pipes. The grooves were 30/1000, 60/1000, and 90/1000 inches in depth. The remaining pipe was a smooth test section with inside diameter of .8 in. The maximum percent increase in Nusselt number over that for a smooth pipe ranged from 22.2% for the 30/1000 section to 55% for the 90/1000 section. The friction factor for the 30/1000 section was found to be approximately 38 percent higher than that of the smooth tube. The friction factor for the 60/1000 and 90/1000 sections were found to be 124 and 181 percent, respectively, higher than that of the smooth section. The most efficient roughened section was that containing the 30/1000 roughness. This section increased the heat transfer by 22 percent over that of the smooth tubing while rendering an increase in the friction factor of 38 percent over the smooth tubing"--Abstract, leaves ii-iii. |
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