Inversion method for measuring multi-hole probe surface pressure distribution of supersonic compressible atmospheric flow field

2021 ◽  
Author(s):  
Yang-chun Zhang ◽  
Shu-dao Zhou ◽  
Song Ye ◽  
Min Wang ◽  
Tao Yao
Keyword(s):  
Flow Field ◽  
Surface Pressure ◽  
Measurement Errors ◽  
Flow Fields ◽  
Parametric Model ◽  
Pressure Probe ◽  
Inversion Method ◽  
Model Errors ◽  
Atmospheric Flow ◽  
Hole Pressure

Abstract The conventional method of measuring a multi-hole probe is based on Bernoulli’s equation and suffers from certain model errors. A computational fluid dynamics (CFD)-based method was used in this study to reduce the theoretical error and establish a parametric model of the surface pressure of a spherical multi-hole pressure probe for measuring compressible flow fields at supersonic velocities. A flow field inversion method based on the parametric model is proposed herein. Numerical simulations were conducted to validate the proposed method. The experiment results show that in the compressible atmospheric flow field within Mach 1.2–1.7, the measurement errors of the inversion method were 1.3% and 2.35% for velocity and angle, respectively, thus verifying the feasibility of the method. Thus, a new method of measuring multi-hole pressure probe atmospheric flow fields was demonstrated.

Experimental Study of Effects of Bowed Blade on the Flow Field in a Cantilevered Stator Passage

2014 ◽  
Author(s):  
Ju Luo ◽  
Jun Hu ◽  
Zhiqiang Wang ◽  
Baofeng Tu
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Flow Field ◽  
Maximum Flow ◽  
Suction Side ◽  
Flow Fields ◽  
Compressor Blade ◽  
Blade Passage ◽  
Hole Pressure ◽  
Passage Vortex

This paper presents experimental investigation conducted on a 2-stage low speed axial research compressor with cantilevered stator vanes. Flow fields at four different axial locations in the radial stacking and bowed stator passage were measured at maximum flow point and near stall point using 4 five-hole pressure probes. The aim of the work is to study the effects of the bowed stators with hub clearance on the flow field of compressor blade passage. The investigations were conducted with the first stage of the compressor. The hub clearances of both original and bowed stators are 1.1% of span. The results show that the scale of the separation vortex, the hub leakage vortex and the lower passage vortex in the bowed blade passage becomes much smaller and the hub leakage vortex is closer to the suction side at near stall point, which causes a much smaller mixing loss in the blade passage.

Effect of Circumferential Inlet Flow Distortion and Swirl on the Flow Field of an Axial Flow Fan Stage

1996 ◽  
Author(s):  
K. Viswanath ◽  
M. Govardhan
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Design Flow ◽  
Flow Coefficient ◽  
Pressure Probe ◽  
Axial Flow Fan ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Hole Pressure ◽  
Inlet Flow Distortion

This paper reports a study of the combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage. The study involves steady state measurements of the flow field at the rotor inlet, exit and the stator exit of the single stage axial flow fan subjected to circumferential inlet flow distortion and swirl. Flow field survey was done at two flow coefficients, namely, ϕ = 0.45 and ϕ = 0.285. The flow at the inlet to the rotor was measured using a three hole pressure probe and five hole pressure probes were used at the rotor and stator exits. The study indicated that at the design flow coefficient swirl had caused deterioration of the performance in addition to that caused by distortion. In addition, the attenuation of distortion was high in the presence of swirl.

Numerical Studies on the Intrusive Influence of a Five-Hole Pressure Probe in a High-Speed Axial Compressor

2017 ◽  
Author(s):  
Christoph Sanders ◽  
Marius Terstegen ◽  
Magnus Hölle ◽  
Peter Jeschke ◽  
Harald Schönenborn ◽  
...  
Keyword(s):  
Mach Number ◽  
Flow Field ◽  
High Speed ◽  
Axial Compressor ◽  
Forced Response ◽  
Rotor Blades ◽  
Pressure Probe ◽  
Maximum Deviation ◽  
Hole Pressure ◽  
Forcing Functions

In this investigation, CFD calculations are conducted to evaluate the differences between five-hole pressure probe-determined flow quantities and the unaffected flow quantities without the probe’s intrusive influence. The blockage effect of the probe is described and evaluated. Furthermore, the influence of this effect is used to estimate the error when using measured stator outflows as forcing functions for the following rotor blades. To compare the flow field, both with and without the probe’s influence, a five-hole pressure probe is traversed numerically at midspan behind each stator row of a 2.5-stage axial compressor. For reproducing the blockage of the probe accurately, the full annulus of the respective stator row has to be modeled. In order to minimize the calculation time, a study to reduce the number of stator passages was successfully performed. To evaluate the flow quantities using the probe, a calibration polynomial is set up numerically. CFD simulations of the probe geometry within a uniform flow field for each pitch and yaw angle, as well as Mach number combination, are performed for this purpose. Moreover, the pressure probe data for the numerical traverses are corrected to account for velocity gradients in the wake region. The comparison of Mach number, with and without the probe’s influence, shows differences both in the width and the depth of the wake. The results of the Fourier-transformed wake profile for both cases are compared and changes in the first harmonic of Mach number of up to −13% identified. Finally, the first harmonic of the flow quantities is used to perform linearized CFD calculations and to evaluate the influence of disturbed forcing functions on the aerodynamic work of the following rotor blade. The average difference in aerodynamic excitation is about −12% with a maximum deviation of more than −30%. The results presented aim to draw attention to intrusive probe influences and their consequences for validating numerical results against experiments. Special attention is given to the discrepancies of forced response calculations with varying gust boundary conditions.

scholarly journals On-board eight-hole pressure probe system to measure wind speed with UAVs

2021 ◽  
Author(s):  
Andrey Shevchenko ◽  
Leonid Afanasiev ◽  
Dmitry Chechin ◽  
Andrey Shmakov
Keyword(s):  
Wind Speed ◽  
Pressure Probe ◽  
Hole Pressure ◽  
Probe System

scholarly journals Incidence Angle and Pitch-Chord Effects on Secondary Flows Downstream of a Turbine Cascade

1992 ◽  
Author(s):  
A. Perdichizzi ◽  
V. Dossena
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Incidence Angle ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Pressure Probe ◽  
Turbine Cascade ◽  
Oil Flow ◽  
Secondary Velocity ◽  
Secondary Flow Field

This paper describes the results of an experimental investigation of the three-dimensional flow downstream of a linear turbine cascade at off-design conditions. The tests have been carried out for five incidence angles from −60 to +35 degrees, and for three pitch-chord ratios: s/c = 0.58,0.73,0.87. Data include blade pressure distributions, oil flow visualizations, and pressure probe measurements. The secondary flow field has been obtained by traversing a miniature five hole probe in a plane located at 50% of an axial chord downstream of the trailing edge. The distributions of local energy loss coefficients, together with vorticity and secondary velocity plots show in detail how much the secondary flow field is modified both by incidence and cascade solidity variations. The level of secondary vorticity and the intensity of the crossflow at the endwall have been found to be strictly related to the blade loading occurring in the blade entrance region. Heavy changes occur in the spanwise distributions of the pitch averaged loss and of the deviation angle, when incidence or pitch-chord ratio is varied.

Numerical Analysis of Flow Fields and Temperature Fields in a Regenerative Heating Furnace for Steel Pipes

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Yi Han ◽  
Feng Liu ◽  
Xin Ran
Keyword(s):  
Temperature Field ◽  
Flow Field ◽  
Flow Velocity ◽  
Gas Flow ◽  
Flow Fields ◽  
Heating Furnace ◽  
Temperature Fields ◽  
Turbulent Layer ◽  
Steel Pipes ◽  
Pipe Blanks

In the production process of large-diameter seamless steel pipes, the blank heating quality before roll piercing has an important effect on whether subsequently conforming piping is produced. Obtaining accurate pipe blank heating temperature fields is the basis for establishing and optimizing a seamless pipe heating schedule. In this paper, the thermal process in a regenerative heating furnace was studied using fluent software, and the distribution laws of the flow field in the furnace and of the temperature field around the pipe blanks were obtained and verified experimentally. The heating furnace for pipe blanks was analyzed from multiple perspectives, including overall flow field, flow fields at different cross sections, and overall temperature field. It was found that the changeover process of the regenerative heating furnace caused the temperature in the upper part of the furnace to fluctuate. Under the pipe blanks, the gas flow was relatively thin, and the flow velocity was relatively low, facilitating the formation of a viscous turbulent layer and thereby inhibiting heat exchange around the pipe blanks. The mutual interference between the gas flow from burners and the return gas from the furnace tail flue led to different flow velocity directions at different positions, and such interference was relatively evident in the middle part of the furnace. A temperature “layering” phenomenon occurred between the upper and lower parts of the pipe blanks. The study in this paper has some significant usefulness for in-depth exploration of the characteristics of regenerative heating furnaces for steel pipes.

Numerical Simulation of Muzzle Flow Field of Gun Based on CFD

2013 ◽  
Vol 291-294 ◽  
pp. 1981-1984
Author(s):  
Zhang Xia Guo ◽  
Yu Tian Pan ◽  
Yong Cun Wang ◽  
Hai Yan Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Stokes Equation ◽  
Wave Structure ◽  
Flow Fields ◽  
Single Equation ◽  
Navier Stokes ◽  
Turbulent Model ◽  
Navier Stokes Equation ◽  
Numerical Simulation Result

Gunpowder was released in an instant when the pill fly out of the shell during the firing, and then formed a complicated flow fields about the muzzle when the gas expanded sharply. Using the 2 d axisymmetric Navier-Stokes equation combined with single equation turbulent model to conduct the numerical simulation of the process of gunpowder gass evacuating out of the shell without muzzle regardless of the pill’s movement. The numerical simulation result was identical with the experimental. Then simulated the evacuating process of gunpowder gass of an artillery with muzzle brake. The result showed complicated wave structure of the flow fields with the muzzle brake and analysed the influence of muzzle brake to the gass flow field distribution.

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