Drawing of Tubes

1980 ◽  
Vol 47 (4) ◽  
pp. 736-740 ◽  
Author(s):  
D. Durban
Keyword(s):  
Exact Solution ◽  
Steady State ◽  
Radial Flow ◽  
Material Behavior ◽  
Wall Friction ◽  
Flow Rule ◽  
Flow Conditions ◽  
Steady State Flow ◽  
Linear Hardening ◽  
Von Mises

The process of the tube drawing between two rough conical walls is analyzed within the framework of continuum plasticity. Material behavior is modeled as rigid/linear-hardening along with the von-Mises flow rule. Assuming a radial flow pattern and steady state flow conditions it becomes possible to obtain an exact solution for the stresses and velocity. Useful relations are derived for practical cases where the nonuniformity induced by wall friction is small. A few restrictions on the validity of the results are discussed.

Axially Symmetric Radial Flow of Rigid/Linear-Hardening Materials

1979 ◽  
Vol 46 (2) ◽  
pp. 322-328 ◽  
Author(s):  
D. Durban
Keyword(s):  
Radial Flow ◽  
Closed Form Solution ◽  
Wire Drawing ◽  
Form Solution ◽  
Flow Rule ◽  
Axially Symmetric ◽  
Linear Hardening ◽  
Stress Components ◽  
Von Mises ◽  
Good Agreement

A closed-form solution has been discovered for axially symmetric radial flow of rigid/linear-hardening materials. It is assumed that the materials obey the von Mises flow rule and that the flow field is in steady state. Explicit expressions for the stress components and the radial velocity are given. The applicability of the solution to wire drawing or extrusion is discussed. Some approximate formulas are derived and shown to be in good agreement, within their range of validity, with experimental results for drawing.

Aeroelasticity at Reversed Flow Conditions: Part 1—Numerical and Experimental Investigations of a Compressor Cascade With Controlled Vibration

2011 ◽  
Author(s):  
Harald Schoenenborn ◽  
Virginie Chenaux ◽  
Peter Ott
Keyword(s):  
Steady State ◽  
Flow Field ◽  
Unsteady Flow ◽  
Steady Flow ◽  
Experimental Investigations ◽  
Blade Surface ◽  
Flow Conditions ◽  
Steady State Flow ◽  
Reversed Flow ◽  
Blow Down

The prediction of flutter and forced response at normal flow conditions has become a standard procedure during the design of compressor airfoils. But at severe off-design conditions, the flow field becomes very complex, especially during the surge blow-down phase where reversed flow conditions occur. The correct prediction of the unsteady pressures and the resulting aerodynamic excitation or damping at these conditions remains an extremely challenging task. In the first part of the paper, basic investigations for these flow conditions are presented. Aeroelastic calculations during compressor surge are shown in the second part. Experimental investigations were performed in the Annular Test Facility for non-rotating cascades at EPF Lausanne. The test cascade was exposed to flow conditions as expected during the surge blow-down phase which is characterized by large separation regions. Measurements of the steady-state flow conditions on the blade surface, at the outer wall, upstream and downstream of the cascade provided detailed information about the steady flow conditions. The cascade was then subjected to controlled vibration of the blades with constant amplitudes and inter-blade phase angles. Unsteady pressure measurements on the blade surface and at the casing wall provided information about the resulting unsteady flow conditions. Analytical CFD calculations were performed. The steady flow field was calculated using a RANS code. Based on the steady-state flow field, unsteady calculations applying a linearized code were carried out. The agreement between measurements and calculations shows that the steady flow as well as the unsteady flow phenomena can be predicted quantitatively. In addition, knowing the blade vibration mode shape, which in this case is a torsion mode, the aerodynamic damping can be determined for the corresponding flow conditions.

Studies on Two-Dimensional Contouring of High-Lift Turbine Airfoil Suction Surface as Separation-Control Device: Separation Suppression Under Steady-State Flow Conditions

2011 ◽  
Author(s):  
Ken-ichi Funazaki ◽  
Nozomi Tanaka ◽  
Takahiro Shiba ◽  
Haruyuki Tanimitsu ◽  
Masaaki Hamabe
Keyword(s):  
Steady State ◽  
Separation Bubble ◽  
Control Device ◽  
Surface Boundary ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Steady State Flow ◽  
Suction Surface ◽  
Airfoil Surface ◽  
State Flow

The study the present authors have been working on is to develop a new method to increase aerodynamic loading of low-pressure turbine airfoils for modern aeroengines to a great extent, which is to achieve drastic reduction of their airfoil counts. For this purpose, this study proposes two-dimensional contouring of the airfoil suction surface as a device to suppress the separation bubble that causes large aerodynamic loss, especially at low Reynolds number condition. The main objective of this paper is to show how and to what extent the surface contouring without any other disturbances affects the suction surface boundary layer accompanying separation bubble. For comparison, rather conventional tripping wire technique is also employed as “local 2D surface contouring” to generate flow disturbances in order to suppress the separation bubble. All measurements are carried out under steady-state flow conditions with low freestream turbulence. It turns out from the detailed experiments and LES analysis that the newly proposed two-dimensional contouring of the airfoil surface can effectively suppress the separation bubble, resulting in significant improvement of cascade aerodynamic performance.

scholarly journals Water collection efficiency of wick samplers under steady state flow conditions

1999 ◽  
Vol 45 (2) ◽  
pp. 485-492 ◽  
Author(s):  
Morihiro Maeda ◽  
Bandunee C. Liyanage ◽  
Yasuo Ozaki
Keyword(s):  
Steady State ◽  
Collection Efficiency ◽  
Flow Conditions ◽  
Steady State Flow ◽  
State Flow ◽  
Water Collection

scholarly journals Relative Permeability of Water and Supercritical CO2 System under Steady-state Flow Conditions in Porous Sandstones

2011 ◽  
Vol 120 (6) ◽  
pp. 944-959 ◽  
Author(s):  
Tetsuya KOGURE ◽  
Keigo KITAMURA ◽  
Tatsuya YAMADA ◽  
Osamu NISHIZAWA ◽  
Ziqiu XUE
Keyword(s):  
Steady State ◽  
Relative Permeability ◽  
Supercritical Co2 ◽  
Flow Conditions ◽  
Steady State Flow ◽  
State Flow

scholarly journals Energy separation in transient and steady-state flow across the cylinder

2018 ◽  
Vol 45 (1) ◽  
pp. 83-94
Author(s):  
Jela Burazer
Keyword(s):  
Fluid Flow ◽  
Steady State ◽  
Energy Equation ◽  
Wake Flow ◽  
Energy Separation ◽  
Cylinder Wake ◽  
Flow Conditions ◽  
Steady State Flow ◽  
State Flow ◽  
Transient And Steady State

Energy separation is a spontaneous energy redistribution within a fluid flow. As a consequence, there are places with higher and lower values of total temperature in the fluid flow. It is characteristic for many flow geometries. This paper deals with the energy separation in a cylinder wake. Two flow conditions are being considered-transient and steady-state flow in the wake. Two different solvers from the open source package OpenFOAM are used in order to capture the phenomenon of energy separation. One of these solvers is modified for the purpose of calculation in a particular case of the vortex street flow. The energy equation based on the internal energy present in this solver is replaced by the energy equation written in the form of a total enthalpy. The other solver has been previously tested in the vortex tube flow, and can also capture the energy separation in the steady-state wake flow of the cylinder. In both cylinder wake flow conditions, a two-dimensional computational domain is used. Standard ?? ? ?? model is used for computations. It is proved that OpenFOAM is capable of capturing the energy separation phenomenon in a proper way in both of the wake flow cases. Good agreement between the experimental results and the ones from computations is obtained in the case of steady-state flow in the wake. Previous research findings are also confirmed in the case of vortex street flow.

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