The Steady Flow Through a Cascade of Closely Spaced Circular Cylinders

1966 ◽  
Vol 70 (669) ◽  
pp. 886-887 ◽  
Author(s):  
B. W. Roberts
Keyword(s):  
Wind Tunnel ◽  
Steady Flow ◽  
Present Note ◽  
Circular Cylinders ◽  
Two Dimensional ◽  
Flow Through

Two recent papers by Bradshaw have drawn attention to instabilities in the flow through wind tunnel screens. In Plate 1 of ref. 2 a smoke tunnel photograph shows the manner in which the jets coalesce behind a high blockage, two-dimensional cascade. In the present note, three points relating to this flow will be discussed.

Two-Dimensional Flow With Standing Vortexes in Ducts and Diffusers

1960 ◽  
Vol 82 (4) ◽  
pp. 921-927 ◽  
Author(s):  
Friedrich O. Ringleb
Keyword(s):  
Wind Tunnel ◽  
Potential Flow ◽  
Separation Control ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Princeton University ◽  
Two Dimensional Flow ◽  
Flow Through ◽  
Trapping Devices

The conditions for the equilibrium of two vortexes in a two-dimensional flow through a duct or diffuser are derived. Potential-flow considerations and a few basic results from viscous-flow theory are used for the discussion of the role of cusps as separation control and trapping devices for standing vortexes. The investigations are applied to cusp diffusers especially with regard to the wind tunnel of the James Forrestal Research Center of Princeton University.

scholarly journals Numerical Analysis of Fluid Flow on Wall Cylinder Circular with K-ε Modeling for a High Reynolds Rate

2019 ◽  
Vol 1 (3) ◽  
pp. 43-50
Author(s):  
M. Yasep Setiawan ◽  
Wawan Purwanto ◽  
Wanda Afnison ◽  
Nuzul Hidayat
Keyword(s):  
Fluid Flow ◽  
Numerical Study ◽  
General Procedure ◽  
Circular Cylinders ◽  
Cylinder Wall ◽  
Two Dimensional ◽  
Third Order ◽  
Physical Information ◽  
Flow Through ◽  
High Reynolds

This study discusses the numerical study of two-dimensional analysis of flow through circular cylinders. The original physical information entered in the equation governing most of the modeling is transferred into a numerical solution. Fluid flow on two-dimensional circular cylinder wall using high Reynolds k-ε modeling (Re = 106), Here we will do 3 modeling first oder upwind, second order upwind and third order MUSCL by using k-ε standard.  The general procedure for this research is formulated in detail for allocations in the dynamic analysis of fluid computing. The results of this study suggest that MUSCL's third order modeling gives more accurate results better than other models.

Performance Predictions of Axial Turbines for Organic Rankine Cycle (ORC) Applications Based on Measurements of the Flow Through Two-Dimensional Cascades of Blades

2014 ◽  
Author(s):  
Karsten Hasselmann ◽  
Felix Reinker ◽  
Stefan aus der Wiesche ◽  
Eugeny Y. Kenig ◽  
Frithjof Dubberke ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Two Dimensional ◽  
Real Gas ◽  
Specific Loss ◽  
Performance Predictions ◽  
Flow Through ◽  
Organic Fluids

The Organic-Rankine-Cycle (ORC) offers a great potential for waste heat recovery and use of low-temperature sources for power generation. However, the ORC thermal efficiency is limited by the relatively low temperature level, and it is, therefore, of major importance to design ORC components with high efficiencies and minimized losses. The use of organic fluids creates new challenges for turbine design, due to real-gas behavior and low speed of sound. The design and performance predictions for steam and gas turbines have been mainly based on measurements and numerical simulations of flow through two-dimensional cascades of blades. In case of ORC turbines and related fluids, such an approach requires the use of specially designed closed cascade wind tunnels. In this contribution, the specific loss mechanisms caused by the organic fluids are reviewed. The concept and design of an ORC cascade wind tunnel are presented. This closed wind tunnel can operate at higher pressure and temperature levels, and this allows for an investigation of typical organic fluids and their real-gas behavior. The choice of suitable test fluids is discussed based on the specific loss mechanisms in ORC turbine cascades. In future work, we are going to exploit large-eddy-simulation (LES) techniques for calculating flow separation and losses. For the validation of this approach and benchmarking different sub-grid models, experimental data of blade cascade tests are crucial. The testing facility is part of a large research project aiming at obtaining loss correlations for performance predictions of ORC turbines and processes, and it is supported by the German Ministry for Education and Research (BMBF).

Effect of Axial Velocity Variation in Aerofoil Cascades

1971 ◽  
Vol 13 (2) ◽  
pp. 92-99 ◽  
Author(s):  
S. Soundranayagam
Keyword(s):  
Wind Tunnel ◽  
Incompressible Flow ◽  
Axial Velocity ◽  
Three Dimensional ◽  
Velocity Variation ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Wind Tunnel Data ◽  
Flow Through

The effect of the variation of axial velocity in the incompressible flow through a cascade of aerofoils is discussed and it is shown that changes take place in the flow angles and in the blade circulation. A method is proposed by which the effect of axial velocity variation on a known two-dimensional flow or alternatively the two-dimensional equivalent of a flow with axial velocity variation can be calculated. The method is very easy to apply. The deviation may increase or decrease depending on the change in blade circulation and the stagger. An increase in apparent deflection through the cascade can be accompanied by a reduction in the blade force. The method would be particularly useful for the interpretation of cascade wind tunnel data and in the design of impeller stages where three-dimensional flows occur.

Some Unresolved Features in the Physics of Quasi Two-Dimensional Flows Over Turbine Blading

2015 ◽  
Author(s):  
J. P. Gostelow ◽  
W. D. E. Allan ◽  
A. Mahallati
Keyword(s):  
Plate Boundary ◽  
Leading Edge ◽  
Circular Cylinders ◽  
Pressure Gradients ◽  
Two Dimensional ◽  
Flat Plates ◽  
Two Dimensional Flow ◽  
Flow Through ◽  
Turbine Blading ◽  
Two Dimensional Flows

Even for the ostensibly two-dimensional flow through cascades of blades, many details of the flow physics are neither well-understood nor well-predicted. Gaps in knowledge are identified that cover entire blade and nozzle vane surfaces from leading edge to trailing edge and beyond. To give improved prediction capability these gaps require improved understanding. The goal of this work is to draw attention to five most significant internal aerodynamic phenomena that affect turbomachinery blade performance and design. By drawing together important experimental results awareness can be raised of these features in blading aerodynamics that are not yet clearly understood. The emphasis is on quasi two-dimensional flows. As well as work on blade cascades this research draws on fundamental investigations over flat plates and circular cylinders. Similar behavior was observed between tests under strong adverse pressure gradients on triggered spots, wake-disturbed flat plate boundary layers, and on turbine blading.

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