An Experimental and Theoretical Investigation of a Twin-Entry Radial Flow Turbine under Non-Steady Flow Conditions

The existence of size effects in small radial flow turbines, such as those used in automotive turbocharger units, has been investigated under steady flow conditions. Three geometrically similar turbines (rotor diameters 101.6, 67.73 and 50.8 mm respectively) have been tested and a ‘size’ effect was observed with the dimensionless mass flow and peak efficiency diminishing with a decrease in rotor diameter. Internal pressure variations were observed in all three turbines which could have a significant influence in relation to blade fatigue failure.

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Performance of Radial Flow Turbines Under Pulsating Flow Conditions

Journal of Engineering for Power ◽

10.1115/1.3446110 ◽

1976 ◽

Vol 98 (1) ◽

pp. 53-59 ◽

Cited By ~ 17

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.

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

Transactions of the Japan Society of Mechanical Engineers ◽

10.1299/kikai1938.44.3497 ◽

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

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Performance of Inward Radial Flow Turbines under Unsteady Flow Conditions with Full and Partial Admission

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1970_185_118_02 ◽

1970 ◽

Vol 185 (1) ◽

pp. 1091-1105 ◽

Cited By ~ 14

Author(s):

F. J. Wallace ◽

J. Miles

Keyword(s):

High Pressure ◽

Unsteady Flow ◽

Steady Flow ◽

Recent Work ◽

Radial Flow ◽

Flow Conditions ◽

Partial Admission ◽

Flow Investigation ◽

Single Entry ◽

Very High

The paper describes the most recent work to be completed in the unsteady flow investigation on radial flow turbines, earlier unsteady flow work for single entry casings having been reported in (1)†and (2), and steady flow work for very high pressure ratios and multiple admission in (3). The present paper combines these analyses to give a coherent treatment of single and multiple admission.

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A particle image velocimetry study on the pulsatile flow characteristics in straight tubes with an asymmetric bulge

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406001523678 ◽

2000 ◽

Vol 214 (5) ◽

pp. 655-671 ◽

Cited By ~ 10

Author(s):

S C M Yu ◽

J B Zhao

Keyword(s):

Particle Image Velocimetry ◽

Steady Flow ◽

Pulsatile Flow ◽

Flow Condition ◽

Particle Image ◽

Flow Characteristics ◽

Reynolds Numbers ◽

Working Fluid ◽

Flow Conditions ◽

Image Velocimetry

Flow characteristics in straight tubes with an asymmetric bulge have been investigated using particle image velocimetry (PIV) over a range of Reynolds numbers from 600 to 1200 and at a Womersley number of 22. A mixture of glycerine and water (approximately 40:60 by volume) was used as the working fluid. The study was carried out because of their relevance in some aspects of physiological flows, such as arterial flow through a sidewall aneurysm. Results for both steady and pulsatile flow conditions were obtained. It was found that at a steady flow condition, a weak recirculating vortex formed inside the bulge. The recirculation became stronger at higher Reynolds numbers but weaker at larger bulge sizes. The centre of the vortex was located close to the distal neck. At pulsatile flow conditions, the vortex appeared and disappeared at different phases of the cycle, and the sequence was only punctuated by strong forward flow behaviour (near the peak flow condition). In particular, strong flow interactions between the parent tube and the bulge were observed during the deceleration phase. Stents and springs were used to dampen the flow movement inside the bulge. It was found that the recirculation vortex could be eliminated completely in steady flow conditions using both devices. However, under pulsatile flow conditions, flow velocities inside the bulge could not be suppressed completely by both devices, but could be reduced by more than 80 per cent.

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Comparison of Experimental and Numerical Simulations of Flow Within an Arterio-Venous Graft

10.1115/imece2000-2617 ◽

2000 ◽

Author(s):

Paul F. Fischer ◽

Seung Lee ◽

Francis Loth ◽

Hisham S. Bassiouny ◽

Nurullah Arslan

Keyword(s):

Flow Field ◽

Steady Flow ◽

Laser Doppler Anemometry ◽

Transition To Turbulence ◽

Flow Conditions ◽

Venous Graft ◽

Venous Anastomosis ◽

Av Graft ◽

Good Agreement

Abstract This was a study to compare computational and experimental results of flow field inside the venous anastomosis of an arteriovenous (AV) graft. Laser Doppler anemometry (LDA) measurements were conducted inside an upscaled end-to-side graft model under steady flow conditions at Reynolds number 1820 which is representative of the in vivo flow conditions inside a human AV graft. The distribution of the velocity and turbulence intensity was measured at several locations in the plane of the bifurcation. This flow field was simulated using computation fluid dynamics (CFD) and shown to be in good agreement. Under steady flow conditions, the flow field demonstrated an unsteady character (transition to turbulence).

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Drawing of Tubes

Journal of Applied Mechanics ◽

10.1115/1.3153783 ◽

1980 ◽

Vol 47 (4) ◽

pp. 736-740 ◽

Cited By ~ 14

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.

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Experimental and Numerical Investigation of Self-Burial Mechanism of Pipeline with Spoiler under Steady Flow Conditions

Journal of Marine Science and Engineering ◽

10.3390/jmse7120456 ◽

2019 ◽

Vol 7 (12) ◽

pp. 456 ◽

Cited By ~ 2

Author(s):

Woo-Dong Lee ◽

Hyo-Jae Jo ◽

Han-Sol Kim ◽

Min-Jun Kang ◽

Kwang-Hyo Jung ◽

...

Keyword(s):

Numerical Analysis ◽

Steady Flow ◽

Pressure Field ◽

Dynamic Pressure ◽

The Self ◽

Navier Stokes ◽

Flow Conditions ◽

Projected Area ◽

Experimental Values ◽

Subsea Pipelines

Herein, hydraulic model experiments and numerical simulations were performed to understand the self-burial mechanism of subsea pipelines with spoilers under steady flow conditions. First, scour characteristics and self-burial functions according to the spoiler length-to-pipe diameter ratio (S/D) were investigated through hydraulic experiments. Further, the Navier–Stokes solver was verified. The experimental values of the velocity at the bottom of the pipeline with a spoiler and the pressure on the sand foundation where the pipeline rested were represented with the degree of conformity. Scour characteristics of a sand foundation were investigated from the numerical analysis results of the velocity and vorticity surrounding the pipelines with spoilers. The compilation of results from the hydraulic experiment and numerical analysis showed that the projected area increased when a spoiler was attached to the subsea pipes. This consequently increased the velocity of fluid leaving the top and bottom of the pipe, and high vorticity was formed within and above the sand foundation. This aggravated scouring at the pipe base and increased the top and bottom asymmetry of the dynamic pressure field, which developed a downward force on the pipeline. These two primary effects acting simultaneously under steady flow conditions explained the self-burial of pipelines with a spoiler attachment.

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Development of a hydraulic conductivity apparatus for bentonite soils

Canadian Geotechnical Journal ◽

10.1139/t07-025 ◽

2007 ◽

Vol 44 (8) ◽

pp. 997-1005 ◽

Cited By ~ 4

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.

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