Investigations Concerning Flow Patterns Within the Impeller Channels of Radial-Inflow Turbines, With Some Reference to the Influence of the Splitter Vanes

1967 ◽  
Vol 89 (4) ◽  
pp. 463-476 ◽  
Author(s):  
Ichiro Ariga ◽  
Ichiro Watanabe ◽  
Kunio Fujie
Keyword(s):  
Experimental Data ◽  
Relative Velocity ◽  
Static Pressure ◽  
Rotation Speed ◽  
Flow Patterns ◽  
Two Dimensional ◽  
Performance Parameters ◽  
Pressure Distributions ◽  
Theoretical Predictions ◽  
Theoretical Results

The experimental results of the relative velocity distributions together with the static pressure distributions within the impeller channels of radial-inflow turbines with and without splitter vanes are presented. The flow patterns within three stream surfaces (blade-to-blade surfaces) having different passage depths are shown using two performance parameters, i.e., nondimensional weight flow and nondimensional rotation speed. The impellers used were of purely radial type or of two-dimensional type. Further, theoretical predictions for the relative velocity distributions within the impeller channels having no splitter vanes were conducted, and comparisons of the theoretical results with experimental data were made.

scholarly journals Investigation Concerning the Blade Loading of Centrifugal Impellers

1974 ◽  
Author(s):  
Shinpei Mizuki ◽  
Ichiro Ariga ◽  
Ichiro Watanabe
Keyword(s):  
Experimental Data ◽  
Secondary Flow ◽  
Theoretical Investigation ◽  
Static Pressure ◽  
Flow Patterns ◽  
Blade Loading ◽  
Pressure Distributions

An investigation concerning the optimum blade loading of centrifugal impellers was performed. The three impellers with straight radial blades employed in the present study were of the same configurations except the shroud profiles which rendered to bring different diffusion ratios from each other. The static pressure distributions on blade surfaces, flow patterns within the impeller channel as well as at impeller inlet and at outlet were measured for these impellers. The effect of a secondary flow within impeller channel was clarified to some extent from the measurements. Theoretical investigation was also performed in order to compare with the experimental data.

Three-dimensional flow in cavities

1963 ◽  
Vol 16 (4) ◽  
pp. 620-632 ◽  
Author(s):  
D. J. Maull ◽  
L. F. East
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Large Span ◽  
Dimensional Flow ◽  
Pressure Distributions ◽  
Oil Flow ◽  
Two Dimensional Flow

The flow inside rectangular and other cavities in a wall has been investigated at low subsonic velocities using oil flow and surface static-pressure distributions. Evidence has been found of regular three-dimensional flows in cavities with large span-to-chord ratios which would normally be considered to have two-dimensional flow near their centre-lines. The dependence of the steadiness of the flow upon the cavity's span as well as its chord and depth has also been observed.

Flow Fields in a Two-Dimensional Diffuser With Extraction of Fluid on the Diverging Walls

1972 ◽  
Vol 94 (3) ◽  
pp. 226-232
Author(s):  
D. O. Rockwell
Keyword(s):  
Experimental Verification ◽  
Static Pressure ◽  
Flow Fields ◽  
Hydrogen Bubble ◽  
Two Dimensional ◽  
Stagnation Region ◽  
Pressure Distributions

A theory is developed to describe the inviscid core in two-dimensional unstalled diffusers with suction (extraction) on the diverging walls. Experimental wall static pressure distributions and streamline patterns agree well with those predicted theoretically. Under appropriate extraction conditions, a stagnation region is located downstream of the diverging wall extraction station. Experimental verification of the streamline patterns and of the location of this stagnation region was achieved via hydrogen bubble visualization. In addition, the possible stall conditions, which result if improper extraction is employed, are described qualitatively.

Thermal Behavior and Friction in Journal Bearings

1970 ◽  
Vol 92 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Al. Nica
Keyword(s):  
Experimental Data ◽  
Thermal Behavior ◽  
Heat Dissipation ◽  
Journal Bearings ◽  
Friction Torque ◽  
Operating Characteristics ◽  
Lubricant Flow ◽  
Theoretical Predictions ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with friction and the field of temperature in the lubricant film of journal bearings. Theoretical results regarding the thermal behavior are checked with experimental data and good agreement is found. Emphasis is put on the variation of temperature and lubricant flow with the operating characteristics of the bearing and it is seen that theoretical predictions for minima of friction torque are backed by temperature measurements. Further on, the friction torque and the mechanism of heat dissipation in bearings are dealt with, in order to verify the assumptions used in the calculation schemes. The means of efficiently cooling the bearing are also discussed, as well as the part played by the divergent zone in this process.

The Normal Approach, Contact, and Rebound of Lubricated Cylinders

1983 ◽  
Vol 105 (2) ◽  
pp. 271-279 ◽  
Author(s):  
A. Chandra ◽  
R. J. Rogers
Keyword(s):  
Experimental Data ◽  
Pressure Distribution ◽  
Constant Load ◽  
Contact Forces ◽  
Solid Model ◽  
Two Dimensional ◽  
Load Case ◽  
Inertia Effects ◽  
Pressure Distributions ◽  
Present Technique

An algorithm has been developed to simulate the normal approach, contact, and rebound of lubricated cylinders. The detailed interaction between the lubricated cylinders is predicted, thus providing the pressure distribution, contact forces, and other variables useful in predicting rates of wear. The present technique improves on the existing elastohydrodynamic (EHD) models in the following areas: (1) during contact a solid-solid model is used; (2) a two-dimensional analysis is used to obtain the pressure distributions in both the circumferential and axial directions; (3) inertia effects are approximated; and (4) any specified load can be treated. The simulated results for the constant load case are compared with the results of Wada and Tsukijihara and a formula developed by Cameron. For sinusoidal loads the results are compared with experimental data from a cylinder and sleeve apparatus.

Influence of a Circumferential Exit Pressure Distortion on the Flow in an Impeller and Diffuser

1987 ◽  
Vol 109 (1) ◽  
pp. 48-54 ◽  
Author(s):  
M. Th. Sideris ◽  
R. A. Van den Braembussche
Keyword(s):  
Experimental Data ◽  
Static Pressure ◽  
Laser Doppler Anemometry ◽  
Theoretical Calculations ◽  
Interaction Model ◽  
Pressure Measurements ◽  
Velocity Measurements ◽  
Local Flow ◽  
Impeller Outlet ◽  
Theoretical Results

Detailed velocity measurements, using Laser Doppler Anemometry (LDA) and static pressure measurements in the vane/ess diffuser of a centrifugal compressor, are presented. They show the relation between the circumferential variation of the pressure and the local flow in the diffuser and at the impeller exit. Theoretical calculations using an impeller-diffuser interaction model have been made. A comparison between the theoretical results and experimental data allows an evaluation of the possibilities and shortcomings of such a calculation. It also illustrates the mechanisms by which the variation of the impeller outlet velocity is defined.

Static Pressure Distributions Over 2D Mast/Sail Geometries

1989 ◽  
Vol 26 (04) ◽  
pp. 333-337
Author(s):  
Stuart Wilkinson
Keyword(s):  
Reynolds Number ◽  
Static Pressure ◽  
Incidence Angle ◽  
Flow Regimes ◽  
Two Dimensional ◽  
Test Program ◽  
Flow Parameters ◽  
Pressure Distributions

A variable-camber aerofoil with integral pressure tappings has been built to investigate the nature of the flows around two-dimensional, highly cambered, sail-like aerofoil sections with circular masts. Data have been obtained in the form of static pressure distributions over representative ranges of Reynolds number, camber ratio, incidence angle, mast diameter/chord ratio and mast angle. Two sail shapes—based on the NACA a = 0.8 and NACA 63 mean-line camber distributions—were involved in the test program. All flow regimes present have been identified and related to the salient model and flow parameters.

A Numerical Treatment for Attached Cavitation

1994 ◽  
Vol 116 (3) ◽  
pp. 613-618 ◽  
Author(s):  
Yongliang Chen ◽  
Stephen D. Heister
Keyword(s):  
Experimental Data ◽  
Wall Pressure ◽  
Two Dimensional ◽  
Numerical Treatment ◽  
Cavitation Model ◽  
Pressure Distributions ◽  
Cavitation Region ◽  
Bubble Length ◽  
Body Shapes ◽  
Two Dimensional Flows

A new numerical treatment has been developed for the prediction of the flowfield resulting from an attached cavitation region. The cavitation model has been implemented in a viscous calculation which is an improvement over previous inviscid results. The model requires no apriori knowledge of the wall detachment point or bubble length and comparisons with experimental data indicate good predictions of these quantities for a variety of different body shapes and cavitation numbers. Furthermore, wall pressure distributions are also predicted quite accurately using this method. While the treatment has been applied to an axisymmetric calculation, the approach should be applicable to two-dimensional flows.

Effect of Shock Boundary Layer Interaction on Aerofoil Pressure Distributions at Transonic Speeds

1963 ◽  
Vol 67 (634) ◽  
pp. 674-677
Author(s):  
D. Tirumalesa
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Turbulent Boundary Layer ◽  
Two Dimensional ◽  
Relative Thickness ◽  
Circular Arc ◽  
Layer Interaction ◽  
Pressure Distributions ◽  
Boundary Layer Interaction ◽  
Theoretical Results

SummaryA method of improving pressure distributions predicted by inviscid theory over two-dimensional aerofoils at transonic speeds taking into account shock-wave turbulent boundary layer interaction as obtained in the case of the flat plate is described.The method was applied to a non-lifting circular arc aerofoil of eight per cent relative thickness. The shock wave location, pressure distribution and drag coefficient were calculated and compared with experimental and inviscid theoretical results.It has been found that the method gives results which are consistent with experimental results in various aspects.

Comparison Between Theoretical Predictions of Wave Resistance and Experimental Data for the Wigley Hull

1983 ◽  
Vol 27 (04) ◽  
pp. 215-226
Author(s):  
C. Y. Chen ◽  
F. Noblesse
Keyword(s):  
Experimental Data ◽  
Froude Number ◽  
Resistance Coefficient ◽  
Wave Resistance ◽  
Number Range ◽  
Theoretical Predictions ◽  
Wigley Hull ◽  
Sinkage And Trim ◽  
Theoretical Results ◽  
Good Agreement

A number of theoretical predictions of the wave-resistance coefficient of the Wigley hull are compared with one another and with available experimental data, to which corrections for sinkage and trim are applied. The averages of eleven sets of experimental data (corrected for sinkage and trim) and of eleven sets of theoretical results for large values of the Froude number, specifically for F 0.266, 0.313, 0.350, 0.402, 0.452, and 0.482, are found to be in fairly good agreement, in spite of considerable scatter in both the experimental data and the numerical results. Furthermore, several sets of theoretical results are fairly close to the average experimental data and the average theoretical predictions for these large values of the Froude number. Discrepancies between theoretical predictions and experimental measurements for small values of the Froude number, specifically for F = 0.18, 0.20, 0.22, 0.24, and 0.266, generally are much larger than for the above-defined high-Froude-number range. However, a notable exception to this general finding is provided by the first-order slender-ship approximation evaluated in Chen and Noblesse [1],3 which is in fairly good agreement with the average experimental data over the entire range of values of Froude number considered in this study.

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