An Experimental Investigation of Secondary Flow in an Accelerating, Rectangular Elbow with 90 Degrees of Turning

An Experimental Investigation of Secondary Flow in an Accelerating, Rectangular Elbow with 90 Degrees of Turning
Author: John D. Stanitz
Publisher:
Total Pages: 684
Release: 1953
Genre: Air flow
ISBN:

The passage vortex associated with secondary flows appears to be near the suction surface and away from the plane wall of the elbow at the exit and does not have appreciable spanwise motion as it moves downstream the elbow exit. As the spoiler size increases, the boundary-layer form changes and a rather sudden difference in the secondary flow occurs, perhaps associated withthe reduced importance of viscous effects in thick boundary layers. It is suggested that the strength of the secondary vortices is small and that the energy of secondary flows is small.

Experimental Study of Flow Distribution and Pressure Loss with Circumferential Inlet and Outlet Manifolds

Experimental Study of Flow Distribution and Pressure Loss with Circumferential Inlet and Outlet Manifolds
Author: Ralph T. Dittrich
Publisher:
Total Pages: 60
Release: 1972
Genre: Fluid dynamics
ISBN:

Water flow tests with circumferential inlet and outlet manifolds were conducted to determine factors affecting fluid distribution and pressure losses. Various orifice sizes and manifold geometries were tested over a range of flow velocities. With inlet manifolds, flow distribution was related directly to orifice discharge coefficients. A correlation indicated that nonuniform distribution resulted when the velocity head ratio at the orifice was not in the range of constant discharge coefficient. With outlet manifolds, nonuniform flow was related to static pressure variations along the manifold. Outlet manifolds had appreciably greater pressure losses than comparable inlet manifolds.

Experimental Investigation of Velocity Distributions Downstream of Single Dust Bends

Experimental Investigation of Velocity Distributions Downstream of Single Dust Bends
Author:
Publisher:
Total Pages: 40
Release: 1948
Genre:
ISBN:

The velocity distribution in curved ducts has been investigated experimentally, notably by Keulegan and Beij (reference 1) and by Kustice (reference 2). The subject is also treated incidentally in numerous investigations of the pressure loss in curved ducts. The available material, however, is neither comprehensive nor does it apply to the types of duct bend found in aircraft installations nor to the range of Reynolds number encountered in their operation.

Analysis and Comparison with Theory of Flow-field Measurements Near a Lifting Rotor in the Langley Full-scale Tunnel

Analysis and Comparison with Theory of Flow-field Measurements Near a Lifting Rotor in the Langley Full-scale Tunnel
Author: Harry H. Heyson
Publisher:
Total Pages: 696
Release: 1956
Genre: Air flow
ISBN:

Results of an investigation in the Langley full-scale tunnel of the induced flow near a lifting rotor are given. Measurements of stream angles and velocities were made in several transverse planes along and behind the rotor in four different conditions representative of the cruising and high-speed ranges of flight. These measurements indicate that available theory may be used to calculate with reasonable accuracy the induced flow over the forward three-quarters of the disk for these flight conditions provided that a realistic nonuniform rotor disk-load distribution is assumed. Rearward of the three-quarter-diameter point, calculations of the induced velocity are increasingly inaccurate due to the rolling up of the trailing-vortex system. Farther rearward, well behind the rotor, the flow may be represented more accurately by the flow behind a uniformly loaded wing.