NACA-TN-3696

A study of the high-speed performance characteristics of 90 degrees bends in circular ducts

contributor author	NASA - National Aeronautics and Space Administration (NASA)
date accessioned	2017-09-04T18:30:58Z
date available	2017-09-04T18:30:58Z
date copyright	01/01/1956
date issued	1956
identifier other	IXONEEAAAAAAAAAA.pdf
identifier uri	http://yse.yabesh.ir/std;jsery=autho47037D83FCDCAC42/handle/yse/213180
description abstract	The performance of four 90° bends in ducts of constant diameter with ratios of radius of curvature to diameter of 0.75, 1.00, 2.50, and 4.00 was investigated over a range of inlet Mach numbers extending up to the choking condition for both a thin and a thick inlet boundary layer. The variation of the measured longitudinal static-pressure gradients at low speed from those predicted by two-dimensional, incompressible, potential flow theory was determined. It was found that an increase in the inlet boundary-layer thickness decreased the choking Mach number by a very small amount for each of the elbows and had little effect on the other performance parameters. It was concluded that, for the type of elbows tested, a mean radius-diameter ratio of approximately 2.50 would yield the greatest inlet choking Mach number with the least loss of static and total pressure.
language	English
title	NACA-TN-3696	num
title	A study of the high-speed performance characteristics of 90 degrees bends in circular ducts	en
type	standard
page	29
status	Active
tree	NASA - National Aeronautics and Space Administration (NASA):;1956
contenttype	fulltext