scholarly journals Discussion: “Performance of Radial Flow Turbines Under Pulsating Flow Conditions” (Kosuge, H., Yamanaka, N., Ariga, I., and Watanabe, I., 1976, ASME J. Eng. Power, 98, pp. 53–59)

1976 ◽  
Vol 98 (1) ◽  
pp. 59-59
Author(s):  
M. G. Kofskey
Keyword(s):  
Radial Flow ◽  
Pulsating Flow ◽  
Flow Conditions

Performance of Radial Flow Turbines Under Pulsating Flow Conditions

1976 ◽  
Vol 98 (1) ◽  
pp. 53-59 ◽  
Author(s):  
H. Kosuge ◽  
N. Yamanaka ◽  
I. Ariga ◽  
I. Watanabe
Keyword(s):  
Steady Flow ◽  
Pressure Pulse ◽  
Radial Flow ◽  
Pressure Ratio ◽  
Pulse Frequency ◽  
Pulsating Flow ◽  
Frequency Range ◽  
Flow Conditions ◽  
Transient Pressure ◽  
Empirical Parameter

Investigations of the pulsating flow performances of an inward radial flow turbine were performed. The quasi-steady flow performances predicted from the measured transient pressure ratio and from steady flow performance data were compared with the measured mean performances under pulsating flow conditions over the pulse frequency range of 30 Hz–70 Hz. The validity of this quasi-steady flow assumption was treated more generally than by the hitherto employed method by adopting a new empirical parameter which indicates both the pressure pulse shape and the amplitude of pressure fluctuation, in addition to the pulse frequency.

scholarly journals Performance of Radial Flow Turbines under Pulsating Flow Conditions : Quasi-Steady Flow Analysis

1978 ◽  
Vol 44 (386) ◽  
pp. 3497-3505
Author(s):  
Hideaki KOSUGE ◽  
Naoharu YAMANAKA ◽  
Ichiro ARIGA ◽  
Ichiro WATANABE
Keyword(s):  
Steady Flow ◽  
Radial Flow ◽  
Flow Analysis ◽  
Pulsating Flow ◽  
Flow Conditions

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.

Development of a hydraulic conductivity apparatus for bentonite soils

2007 ◽  
Vol 44 (8) ◽  
pp. 997-1005 ◽  
Author(s):  
Greg Siemens ◽  
James A. Blatz
Keyword(s):  
Hydraulic Conductivity ◽  
Radial Flow ◽  
Control Volume ◽  
Flow Conditions ◽  
Displacement Boundary ◽  
Simultaneous Control ◽  
Swelling Soil ◽  
Complicated Process ◽  
Post Test ◽  
Stress States

Measurement and interpretation of hydraulic conductivity in porous media is a complicated process, and many laboratory apparatuses exist for different soil types and conditions. To use models for interpretation and prediction of hydraulic conductivity, accurate test measurements are required. A new hydraulic conductivity apparatus is presented that includes simultaneous control of volume and stress states. The apparatus includes the ability to automatically control volume to apply selected displacement boundary conditions while imposing radial flow conditions. The capabilities of the system are displayed using two selected hydraulic conductivity tests on an unsaturated sand–bentonite mixture, which is a swelling soil. Hydraulic conductivity on the order of 10−13 m/s was measured using the new system and compared closely with previously measured values using a similar material. Post-test measurements displayed internal water content, density, and saturation changes that occurred during testing.

Pulsating Flow in a Channel With a Backward-Facing Step

1997 ◽  
Vol 50 (11S) ◽  
pp. S232-S236
Author(s):  
Alvaro Valencia
Keyword(s):  
Vortex Breakdown ◽  
Separation Zone ◽  
Pulsating Flow ◽  
Steady Flows ◽  
Reattachment Length ◽  
Flow Conditions ◽  
Backward Facing Step ◽  
Primary Vortex ◽  
Inlet Flow ◽  
Inlet Velocity

The incompressible laminar flow in a channel with a backward-facing step is studied for steady cases and for pulsating inlet flow conditions. For steady flows, the influrnce of the inlet velocity profile, the height of the step, and the Reynolds number on the reattachment length is investigated. A parabolic entrance profile was used for pulsating flow. It was found with amplitude of oscillation of one by Re = 100 that the primary vortex breakdown through one pulsatile cycle and the wall shear stress in the separation zone varied markedly with pulsating inlet flow.

Radial Turbine Rotor Response to Pulsating Inlet Flows

2013 ◽  
Vol 136 (7) ◽  
Author(s):  
Teng Cao ◽  
Liping Xu ◽  
Mingyang Yang ◽  
Ricardo F. Martinez-Botas
Keyword(s):  
Numerical Method ◽  
Time Lag ◽  
Turbine Rotor ◽  
Pulsating Flow ◽  
Navier Stokes ◽  
Transient Effects ◽  
Flow Conditions ◽  
Radial Turbine ◽  
Reduced Frequency ◽  
Integrated Performance

The performance of automotive turbocharger turbines has long been realized to be quite different under pulsating flow conditions compared to that under the equivalent steady and quasi-steady conditions on which the conventional design concept is based. However, the mechanisms of this phenomenon are still intensively investigated nowadays. This paper presents an investigation of the response of a stand-alone rotor to inlet pulsating flow conditions by using a validated unsteady Reynolds-averaged Navier–Stokes solver (URANS). The effects of the frequency, the amplitude, and the temporal gradient of pulse waves on the instantaneous and cycle integrated performance of a radial turbine rotor in isolation were studied, decoupled from the upstream turbine volute. A numerical method was used to help gain the physical understanding of these effects. A validation of the numerical method against the experiments on a full configuration of the turbine was performed prior to the numerical tool being used in the investigation. The rotor was then taken out to be studied in isolation. The results show that the turbine rotor alone can be treated as a quasi-steady device only in terms of cycle integrated performance; however, instantaneously, the rotor behaves unsteadily, which increasingly deviates from the quasi-steady performance as the local reduced frequency of the pulsating wave is increased. This deviation is dominated by the effect of quasi-steady time lag; at higher local reduced frequency, the transient effects also become significant. Based on this study, an interpretation and a model of estimating the quasi-steady time lag have been proposed; a criterion for unsteadiness based on the temporal local reduced frequency concept is developed, which reduces to the Λ criterion proposed in the published literature when cycle averaged. This in turn emphasizes the importance of the pressure wave gradient in time.

scholarly journals 3-D Modelling and Experimental Comparison of Reactive Flow in Carbonates under Radial Flow Conditions

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Piyang Liu ◽  
Jun Yao ◽  
Gary Douglas Couples ◽  
Jingsheng Ma ◽  
Oleg Iliev
Keyword(s):  
Radial Flow ◽  
Experimental Comparison ◽  
Reactive Flow ◽  
Flow Conditions

scholarly journals Polymorph Selection of ROY by Flow-Driven Crystallization

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 351 ◽  
Author(s):  
Ziemecka ◽  
Gokalp ◽  
Stroobants ◽  
Brau ◽  
Maes ◽  
...  
Keyword(s):  
Radial Flow ◽  
Outer Edge ◽  
Local Concentration ◽  
Equilibrium Flow ◽  
Confined Space ◽  
Flow Conditions ◽  
Flow Rates ◽  
Polymorph Selection ◽  
Displacement Pattern ◽  
Selection Of

The selection of polymorphs of the organic compound 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, ROY, is studied experimentally in the confined space between two horizontal glass plates when an acetone solution of ROY of variable concentration is injected at a variable flow rate into water. Depending on the local concentration within the radial flow, a polymorph selection is observed such that red prisms are favored close to the injection center while yellow needles are the preferred polymorph close to the edge of the injected ROY domain. At larger flow rates, a buoyancy-driven instability induces stripes at the outer edge of the displacement pattern, in which specific polymorphs are seen to crystallize. Our results evidence the possibility of a selection of ROY polymorph structures in out-of-equilibrium flow conditions.

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