Turbulent boundary-layer flow on a rotating disk

1969 ◽  
Vol 37 (1) ◽  
pp. 129-147 ◽  
Author(s):  
T-S. Cham ◽  
M. R. Head

Calculations have been made of the development of the turbulent boundary layer on a disk rotating in free air, using circumferential and radial momentum-integral equations and an auxiliary equation of entrainment. In the calculations, circumferential velocity profiles are represented by Thompson's (1965) two-parameter family, while radial profiles are given by Mager's (1952) quadratic expression. The circumferential component of skin friction follows from the use of Thompson's profile family for the circumferential velocity. The entrainment, in dimensionless form, is assumed to be determined uniquely by the circumferential velocity profile in the same way as was proposed by Head (1958) for a two-dimensional turbulent boundary layer.Detailed measurements have been made of the development of the turbulent boundary layer on the rotating disk, and the calculations are found to be in excellent agreement with the results when a suitable adjustment is made to Head's two-dimensional entrainment curve.

1975 ◽  
Vol 189 (1) ◽  
pp. 305-315 ◽  
Author(s):  
T. J. Kotas

A presentation of some measurements of velocities in the turbulent boundary layer on the end wall of a vortex chamber. These show that the boundary layer flow is three-dimensional with large inward radial velocities. Consequently, most of the fluid entering the vortex chamber passes into the central region through the boundary layers on the end walls rather than the main space of the vortex chamber. A momentum integral solution is used to obtain an estimate of the radial flow through the end-wall boundary layers. A comparison of the theoretical curves with the experimental results gives support to the main assumptions used in the solutions.


1967 ◽  
Vol 18 (2) ◽  
pp. 150-164 ◽  
Author(s):  
N. A. Cumpsty ◽  
M. R. Head

SummaryAn earlier paper described a method of calculating the turbulent boundary layer flow over the rear of an infinite swept wing. It made use of an entrainment equation and momentum integral equations in streamwise and cross-flow directions, together with several auxiliary assumptions. Here the method is adapted to the calculation of the turbulent boundary layer flow along the attachment line of an infinite swept wing. In this case the cross-flow momentum integral equation reduces to the identity 0 = 0 and must be replaced by its differentiated form. Two alternative approaches are also adopted and give very similar results, in good agreement with the limited experimental data available. It is found that results can be expressed as functions of a single parameter C*, which is evidently the criterion of similarity for attachment-line flows.


Author(s):  
Bao-Shi Shiau ◽  
Ben-Jue Tsai

Experimental measurement study on the structure of the Reynolds stress and turbulence spectrum for wind flows over a two-dimensional escarpment with mild upwind slope (slope angle θ = 15°) were performed in the wind tunnel. The Quadrant analysis was applied to analyze the experimental data and yield the structure of the Reynolds stress. In according to the quadrant analysis, the Reynolds stress is composed of four events of the stress components, i.e. outward interaction, ejection (low-speed fluid upward), inward interaction, and sweep (high-speed fluid downward). Measured results show that: (1) Measurements of the structure of the Reynolds stress reveal that both the sweep and ejection events are the major contributors to the Reynolds stress for flow around the two dimensional escarpment with mild upwind slope. (2) The contributions to the Reynolds stress made by ejection events and sweep events are almost the same at heights Z/Zref greater than 0.2 for different downstream distances along the mild slope of escarpment. Here Zref is the turbulent boundary layer thickness. When flow reached the top of the slope of escarpment, stress fractions of ejection event and sweep event, S2 and S4 increased significantly. (3) The he turbulent energy spectrum distribution was not found very dominant spectrum peak as winds flow over the mild upwind slope and top surface of escarpment.


1974 ◽  
Vol 16 (2) ◽  
pp. 71-78 ◽  
Author(s):  
W. K. Allan ◽  
V. Sharma

Experimental data for two-dimensional, low-speed, turbulent boundary layer flow has been used to verify the description of mean-velocity distributions proposed by Allan and to re-evaluate the entrainment function. The independence of pressure gradient and surface roughness as regards their effects on velocity profiles has been demonstrated. Boundary layer predictions agree with experimental data for a smooth surface, but further investigation is required for flow over a rough surface.


1982 ◽  
Vol 104 (2) ◽  
pp. 156-160 ◽  
Author(s):  
J. E. McAllister ◽  
F. J. Pierce ◽  
M. H. Tennant

Preston tubes provide a convenient means of estimating local wall shear stress. Practical difficulties arise from a lack of calibration data obtained in turbulent boundary layer flows and from the wide choice of calibration equations available mainly from pipe flow calibrations. The results of an experimental study comparing a large number of direct force local wall shear stress measurements in a near-zero pressure gradient two-dimensional turbulent boundary layer flow are presented. The results indicate that there is consistent and excellent agreement between the Patel intermediate calibration formula and the direct force measurements. Typical differences among the direct force measurements and several other proposed calibration equations are also shown.


Sign in / Sign up

Export Citation Format

Share Document