Visualization of supersonic flows by means of a prebreakdown discharge

Алферов, В. И.; Kalachev, B. V.

doi:10.1007/bf00912748

Cited by 2 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Local radiation intensity of discharge plasma I(x,y,z) at a certain time instant is: I(x,y,z,)= f (W, U, i, N, P, T, d, Se) Where W is the electrical energy supplied to the discharge area, U is the voltage between the electrodes, i is the discharge current, N is the particle density, P is the pressure, T is the temperature, d is the distance between the electrodes in mm, Se is the parameter characterizing the geometry of the electrodes. Since the 1950th, flow studies have been carried out around various models in TsAGI wind tunnels using a stationary high-voltage discharges [34][35][36][37]. In particular, stationary shock waves were visualized in the flow around the cone model on a cylindrical holder at different angles of attack.…”

Section: Gas Discharge Flow Visualizationmentioning

confidence: 99%

Methods for Panoramic Visualization and Digital Analysis of Thermophysical Flow Fields. A Review.

Znamenskaya¹

2021

View full text Add to dashboard Cite

The paper presents a review of modern methods in the registration, processing, and analysis of dynamic processes in liquids, gases, plasmas, multiphase media, which are realized in researches and technology. The review author observes both the physical fundamentals of flow visualization and the basics of modern technologies for digital processing of recorded flow images. A brief analysis of the panoramic visualization methods progress history covers a period of one and a half centuries. In the works of the last decade, the focus is on the methods of computer processing, tools, technologies for analyzing and recognizing of panoramic thermophysical fields, which make it possible to obtain quantitative information about flows. The review contains an analysis of publications describing the main modern methods of visualization of flows: methods based on the phenomenon of refraction; electroluminescence; on digital tracing (particle image velocimetry), visualization of surface flows (PSP and TSP coatings, liquid crystals; oil coatings). Particular attention is paid to methods using crosscorrelation image processing algorithms. Those are: digital tracing (PIV), shadow background method (in English Background Oriented Schlieren -BOS), seedless shadow methods, thermographic PIV, velocity measurement in viscous coatings, micro, tomographic modifications of PIV, etc. The actual problem of digital data analyzing in a panoramic experiment is touched upon -the problem of big data. Examples of the machine learning use in the analysis of big data sets of shadow surveys are given. Some examples of numerical simulation data visualization (simulation of experimental flowfields) are considered.

show abstract

Section: Gas Discharge Flow Visualizationmentioning

confidence: 99%

Methods for Panoramic Visualization and Digital Analysis of Thermophysical Flow Fields. A Review.

Znamenskaya¹

2021

View full text Add to dashboard Cite

show abstract

“…Indeed the excitation function of the gas molecules depends weakly on the electron energy in the range of energies which are usually used for visualizations. Hence, even though electron energy changes when transferring from regions with different densities due to change in the mean free path, the intensity of the glow depends only on the number of gas molecules per unit volume for a fixed electron number [5]. Therefore the visualization by glow discharge technique is based upon the use of light emitted when gas molecules are de-excited.…”

Section: Introductionmentioning

confidence: 99%

“…Alferov and Kalachev [5] have observed different flow patterns when the model is placed in the glow region of the discharge, particularly in the case of diffuse discharge. This has also been observed and explained by Merriman and Palm [15].…”

Section: Introductionmentioning

confidence: 99%

Visualization by discharge illumination technique and modification by plasma actuator of rarefied Mach 2 airflow around a cylinder

Léger

Sellam

Barbosa

et al. 2013

Meas. Sci. Technol.

View full text Add to dashboard Cite

The use of plasma actuators for flow control has received considerable attention in recent years. This kind of device seems to be an appropriate means of raising abilities in flow control thanks to total electric control, no moving parts and a fast response time. The experimental work presented here shows, firstly, the non-intrusive character of the visualization of the density field of an airflow around a cylinder obtained using a plasma luminescence technique. Experiments are made in a continuous supersonic wind tunnel. The static pressure in the flow is 8 Pa, the mean free path is about 0.3 mm and the airflow velocity is 510 m s−1. Pressure measurements obtained by means of glass Pitot tube without the visualization discharge are proposed. Measured and simulated pressure profiles are in good agreement in the region near the cylinder. There is good correlation between numerical simulations of the supersonic flow field, analytical model predictions and experimental flow visualizations obtained by a plasma luminescence technique. Consequently, we show that the plasma luminescence technique is non-intrusive. Secondly, the effect of a dc discharge on a supersonic rarefied air flow around a cylinder is studied. An electrode is flush mounted on the cylinder. Stagnation pressure profiles are examined for different electrode positions on the cylinder. A shock wave modification depending on the electrode location is observed. The discharge placed at the upstream stagnation point induces an upstream shift of the bow shock, whereas a modification of the shock wave shape is observed when it is placed at 45° or 90°.

show abstract

Visualization of supersonic flows by means of a prebreakdown discharge

Cited by 2 publications

References 2 publications

Methods for Panoramic Visualization and Digital Analysis of Thermophysical Flow Fields. A Review.

Methods for Panoramic Visualization and Digital Analysis of Thermophysical Flow Fields. A Review.

Visualization by discharge illumination technique and modification by plasma actuator of rarefied Mach 2 airflow around a cylinder

Contact Info

Product

Resources

About