Research on the influence of contraction curve on the flow field performance of Laval nozzle

The present paper deals with the numerical and experimental investigation of the effect of return channel (RCH) dimensions of a centrifugal compressor stage on the aerodynamic performance. Three different return channel stages were investigated, two stages comprising three-dimensional (3D) return channel blades and one stage comprising two-dimensional (2D) RCH vanes. The analysis was performed regarding both the investigation of overall performance (stage efficiency, RCH total pressure loss coefficient) and detailed flow-field performance. For detailed experimental flow-field investigation at the stage exit, six circumferentially traversed three-hole probes were positioned downstream the return channel exit in order to get two-dimensional flow-field information. Additionally, static pressure wall measurements were taken at the hub and shroud pressure and suction side (SS) of the 2D and 3D return channel blades. The return channel system overall performance was calculated by measurements of the circumferentially averaged 1D flow field downstream the diffuser exit and downstream the stage exit. Dependent on the type of return channel blade, the numerical and experimental results show a significant effect on the flow field overall and detail performance. In general, satisfactory agreement between computational fluid dynamics (CFD)-prediction and test-rig measurements was achieved regarding overall and flow-field performance. In comparison with the measurements, the CFD-calculated stage performance (efficiency and pressure rise coefficient) of all the 3D-RCH stages was slightly overpredicted. Very good agreement between CFD and measurement results was found for the static pressure distribution on the RCH wall surfaces while small CFD-deviations occur in the measured flow angle at the stage exit, dependent on the turbulence model selected.

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Exploring the Behavior of a Coherent Flow Field Produced by a Shrouding Laval Nozzle Structure

ISIJ International ◽

10.2355/isijinternational.isijint-2019-182 ◽

2020 ◽

Vol 60 (4) ◽

pp. 682-690

Author(s):

Fuhai Liu ◽

Dongbai Sun ◽

Rong Zhu ◽

Shaoyan Hu

Keyword(s):

Flow Field ◽

Laval Nozzle ◽

Nozzle Structure

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Numerical and Experimental Investigation of Return Channel Vane Aerodynamics With 2D and 3D Vanes

Volume 2D: Turbomachinery ◽

10.1115/gt2016-57713 ◽

2016 ◽

Author(s):

A. Hildebrandt ◽

F. Schilling

Keyword(s):

Experimental Investigation ◽

Flow Field ◽

Static Pressure ◽

Pressure Rise ◽

Field Performance ◽

Two Dimensional ◽

Flow Angle ◽

Overall Performance ◽

Return Channel ◽

2D And 3D

The present paper deals with the numerical and experimental investigation of the effect of return channel dimensions of a centrifugal compressor stage on the aerodynamic performance. Three different return channel stages were investigated, two stages comprising 3D (three-dimensional) return channel blades and one stage comprising (2D) two-dimensional RCH (Return Channel) vanes. The analysis was performed regarding both the investigation of overall performance (stage efficiency, RCH total pressure loss coefficient) and detailed flow field performance. For detailed experimental flow field investigation at the stage exit, six circumferentially traversed three-hole probes were positioned downstream the return channel exit in order to get two-dimensional flow field information. Additionally, static pressure wall measurements were taken at the hub and shroud pressure and suction side of the 2D and 3D return channel blades. The return channel system overall performance was calculated by measurements of the circumferentially averaged 1D flow field downstream the diffuser exit and downstream the stage exit. Dependent on the type of return channel blade, the numerical and experimental results show a significant effect on the flow field overall and detail performance. In general, satisfactory agreement between CFD-prediction and test-rig measurements was achieved regarding overall and flow field performance. In comparison with the measurements, the CFD calculated stage performance (efficiency and pressure rise coefficient) of all 3D-RCH stages was slightly over-predicted. Very good agreement between CFD and measurement results was found for the static pressure distribution on the RCH wall surfaces while small CFD-deviations occur in the measured flow angle at the stage exit, dependent on the turbulence model selected.

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Simulation of the Effect of Process Parameters on Particle Velocity in Cold Spray Using Laval Nozzle with Nine Holes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.78 ◽

2011 ◽

Vol 314-316 ◽

pp. 78-81

Author(s):

Chuan Shao Liu ◽

Yao Hui Jin ◽

Jian Xin Zheng

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Supersonic Flow ◽

Flow Field ◽

Particle Velocity ◽

Laval Nozzle ◽

Particle Diameter ◽

Standoff Distance ◽

Single Hole ◽

Dynamics Method

Simulations of the supersonic flow field inside and outside of the Laval nozzle with single hole and nine holes were carried out based on the computational fluid dynamics method. The effects of different standoff distance and particle diameter on impact velocity of Cu particle spraying from single hole and nine holes were investigated firstly. The results show that the particle velocity obtained with the nine holes nozzle is higher than that of the single hole nozzle under the same standoff distance, and the smaller the standoff distance, the higher the particle velocity may be obtained with the nine holes, and the higher particle velocity may be obtained with smaller particle diameter for particles with diameters of 1 ~ 15 μm. Furthermore the effects of different spraying pressure and temperature on particle velocity of Cu particle spraying from the nine holes nozzle were also studied. And the simulations indicate that the higher the spraying pressure and temperature may make the particle spraying with greater velocity.

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Relativity Research of Total Pressure and Regulating Valve in Continuous Wind Tunnel and Its Application

Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University ◽

10.1051/jnwpu/20203820325 ◽

2020 ◽

Vol 38 (2) ◽

pp. 325-332

Author(s):

Dan Chen ◽

Xiaosong Yang ◽

Gang Li ◽

Shouchun Guo ◽

Tianyi Chen

Keyword(s):

Wind Tunnel ◽

Flow Field ◽

Total Pressure ◽

Position Control ◽

Flow Characteristics ◽

Field Performance ◽

Pressure Control ◽

Static Test ◽

Polar Curve ◽

Transonic Wind Tunnel

As the main adjusting means of the total pressure for the continuous transonic wind tunnel, the characteristics of regulating valve directly affect the flow field performance of the wind tunnel, therefore, it is important to analyze and establish the correlation between the regulating valve and the total pressure, and it is necessary to select the appropriate regulating valve and its combination accordingly. Firstly, in terms of the pressure regulation principle of the wind tunnel pressure regulating system, combining with the flow characteristics of the regulating valve, the correlation between the position control of the regulating valve and the total pressure control of the wind tunnel is established, then the static test is conducted to verify the relationship. In order to shorten the flow field stability time under the negative pressure of 0.6m continuous transonic wind tunnel, based on the established theory, the valve system is optimized and reformed, and the blowing test is carried out. The results show that the time of optimized Mach number polar curve decreases by 40%~50%, which greatly improves the test efficiency, which further proves that the present analysis is correct and effective, and can provide reference for the design of pressure regulating system in continuous transonic wind tunnel.

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