Effects Of Shock Waves Research Articles

External stimulation: A potential therapeutic strategy for tendon-bone healing.

Injuries at the tendon-bone interface are very common in the field of sports medicine, and healing at the tendon-bone interface is complex. Injuries to the tendon-bone interface can seriously affect a patient's quality of life, so it is essential to restore stability and promote healing of the tendon-bone interface. In addition to surgical treatment, the healing of tendons and bones can also be properly combined with extracorporeal stimulation therapy during the recovery process. In this review, we discuss the effects of extracorporeal shock waves (ESWs), low-intensity pulsed ultrasound (LIPUS), and mechanical stress on tendon-bone healing, focusing on the possible mechanisms of action of mechanical stress on tendon-bone healing in terms of transcription factors and biomolecules. The aim is to provide possible therapeutic approaches for subsequent clinical treatment.

The effect of shock waves on mineralization and regeneration of distraction zone in osteoporotic rabbits

Objective Osteoporotic individuals suffer from various complications such as spontaneous bone fractures due to decreased bone strength and failure in bone healing as a result of decreased bone mineral density and deterioration of bone microstructure. In this study, the effects of Extracorporeal Shock Wave Therapy (ESWT) in a distraction osteogenesis model in osteoporotic rabbits were investigated to prevent these failures and improve bone microstructure. Material and Methods A total of 28 female New Zealand rabbits underwent mandibular distraction osteogenesis and were divided into four groups: non-ovariectomized control (Cont), ovariectomized control (O-Cont), ovariectomized ESWT1 (O-ESWT1) and ovariectomized ESWT2 (O-ESWT2). ESWT was only applied to the ESWT2 group before the osteotomy, and to both the ESWT1 and ESWT2 groups after the osteotomy. Dual-energy x-ray absorptiometry was used to determine bone mineral density on both the 7th and 28th day of the consolidation. Stereological methods were used to identify new bone formation, connective tissue and neoangiogenesis volume. Results According to the dual-energy x-ray absorptiometry examination both at the 7th and 28th day of the consolidation, lower bone mineral density was seen in the ESWT groups. However, the stereological examination showed that shock wave therapy significantly increased new bone formation both ESWT1 and ESWT2 compared with O-Cont, significantly increased neoangiogenesis in O-ESWT1 compared with O-Cont. Conclusions The application of ESWT in these parameters after osteotomy was beneficial for bone regeneration in mandibular distraction in osteoporotics. However, ESWT has been shown to be ineffective in improving bone mineral density. KEY MESSAGES The osteoporotic model can be successfully established in rabbits and the subjects can tolerate the distraction procedures. Stereology is a useful analysis method that can determine the volume of the new bone formation and neoangiogenesis. Extracorporeal shock wave therapy has biostimulatory effects on bone tissue.

Process optimisation of cold spray additive manufacturing of FeCoNiCrMn high-entropy alloy

ABSTRACT The deposition window of cold spray additive manufacturing (CSAM) a high-entropy alloy (HEA) was optimised by investigating processing parameters on deposition efficiency and porosity. The optimal parameters were obtained with helium as the driving gas, gas inlet temperature was at 700°C, and spray distance at 25 mm, at which the deposit was the thickest and of the lowest porosity. The type of driving gas is critical as it affects the porosity and deposition efficiency, and helium is required to obtain high-quality HEA deposits. With it, gas inlet temperature and spray distance have a minimal effect. Furthermore, higher gas temperature and moderate spraying distance were selected to increase particle deformation and reduce the effect of shock waves at the plate front.

Two laser beam modulation of microstructure and residual stress field in cold sprayed Al alloy for recovering fatigue performance

The cold spray (CS) process has been demonstrated to be an attractive additive manufacturing technology for the development of freeforms and coatings from temperature-sensitive materials. However, owing to the lower bonding strength and inhomogeneous residual stress field distribution, the fatigue performance of CS deposition cannot satisfy the requirements of numerous engineering conditions. This study proposes a novel and promising approach to recover the fatigue performance of CS-repaired Al alloy components using two laser beam modulations. In the treatment, a millisecond laser is used during the CS process to heat the impact location in situ, by which the bonding mode is transformed from mechanical bonding to metallurgical bonding, and massive Al2O3 reinforcements of nano/micro size are formed in the coating. Thus, the bonding strength is significantly improved. Next, another nanosecond laser is used as a post-treatment to act on the area except the repaired region of the sample, which optimised the residual stress distribution around the repaired zone by the mechanical effects of the laser-induced ultra-high shock waves. Through the combination of these two lasers, the fatigue performance of CS-repaired Al alloy samples is successfully restored to its original condition. This study demonstrates that this compound process of CS technology and laser processing presents a wide range of possibilities for further development of advanced repair technology.

Детонационные процессы во фронте горения растительных горючих материалов

Представлены результаты экспериментального исследования воздействия ударной волны на пламя при горении растительных горючих материалов. Ударная волна формировалась с помощью ударной трубы с различными насадками и источником энергии от порохового заряда. Для регистрации воздействия ударной волны на зону пиролиза применялись методы высокоскоростной ИК термографии в узкополосном диапазоне длины волны 2,5–2,7 мкм. Установлено, что при применении расширяющихся насадков в результате воздействия ударной волны на зону пиролиза происходит детонация продуктов пиролиза, которая приводит к прекращению пламенного горения. Much attention is currently being paid worldwide to improvement of existing and developing new effective ways to fight effectively natural fires, which occur annually in different countries and on a variety of landscapes. Given the annual increase in the number of wildfires and the often catastrophic consequences from them, it can be stated that the existing methods of firefighting are not effective enough. The methods used to extinguish large fires are usually based on the discharge of water by aircraft and the involvement of a large amount of manual labor of firefighters. This work is devoted to the study of the issue of extinguishing a natural fire by the impact of a shock wave on the burning zone. At present, the question of the interaction of the compaction shockwave with the flame during the combustion of plant combustible materials remains practically unstudied. Existing works in the field of shock waves impact on the fire front are limited to estimates of disruption of combustion conductors and formation of mineralized band. Modern research tools and methods allow to record and visualize the rapid processes, including in the flame. In particular, modern methods of infrared thermography make it possible to study both the temperature field in the flame and the structure of flow in it. Based on the original methods and approaches for application of high-speed infrared thermography developed at Tomsk State University, this work presents the results of an experimental study of the shock wave effect on the flame during combustion of plant flammable materials. A shock tube with different nozzles and an energy source from a gunpowder charge were used to form the shock wave. The impact of the shock wave on the pyrolysis zone was recorded in the narrow band infrared wavelength range of 2.5–2.7 μm. It has been established that the impact of the shock wave on the pyrolysis zone, when expanding nozzles are used, results in the detonation of pyrolysis products, which leads to the cessation of flame combustion and subsequent decrease in the surface temperature of plant combustibles below the autoignition temperature. This effect leads to a break in the chain of transformation and energy release during combustion. The obtained result should be considered as a fundamental basis for the development of new effective means of extinguishing large natural fires based on the impact of a shock wave.

Study on damage effect of caisson wharves subjected to underwater explosion

This study aimed at investigating the destructive effect of explosion shock waves on caisson wharves in shallow water. First, underwater explosion tests were conducted on caisson wharves, full-size finite-element models of caisson wharf-water-explosive were established, and the accuracy of the models was verified by comparison. The destruction pattern and damage characteristics of the caisson wharf structure were then studied, and the effects of different explosion depths and different explosive quantities on the dynamic response of caisson wharves were analyzed. The results show that the destruction pattern of shock waves on the caisson wharf is manifested as plastic damage at the joint of the reinforced concrete (RC) box wall, shear destruction at the lower edge of the explosion loading wall, and integral displacement of the superstructure. When the scaled distance remains unchanged and the explosion depth and explosive quantity increase, the bottom reflection effect strengthens, turning the bending damage on the explosion loading wall into shear damage. By strengthening the performance of the RC box wall joints, explosion loading wall, and superstructure joints, and taking measures to reduce the reflection effect, the anti-explosion capacity of caisson wharves can be effectively improved.

Study on the effect, safety, prognosis quality and application value of extracorporeal shock wave based neural activity in carpal tunnel syndrome patients

BackgroundMild to moderate CTS is the most common median nerve compression disease in middle-aged and elderly women, mainly manifested by hand numbness and pain. This paper analyzes the extracorporeal shock wave of patients with mild to moderate CTS after nerve mobilization.MethodsThe clinical data of 92 patients with CTS from June 2020 to June 2022 are analyzed and randomly divided into extracorporeal shock wave group (n = 47) and routine group (n = 45). The routine group undergoes nerve mobilization, and the extracorporeal shock wave group receives extracorporeal shock wave therapy on the basis of the routine group. The clinical efficacy, symptom improvement, pain score, median nerve electrophysiological examination results, upper limb symptom and function scores, and ADL scores before and after treatment are observed. The Spearman correlation coefficient is used to analyze the correlation between upper limb function and ADL score, and the incidence of complications after treatment is analyzed.ResultsThe clinical efficacy, symptom improvement, pain score, median nerve electrophysiological examination results, upper limb symptom and function score, ADL score and the incidence of complications in the extracorporeal shock wave group are significantly better than those in the conventional group (P < 0.05). ADL scores are negatively correlated.ConclusionExtracorporeal shock wave combined with nerve mobilization has a significant effect in the treatment of CTS patients, which can significantly improve the symptoms and pain scores of patients, and enhance the function of patients’ upper limbs. At the same time, the incidence of complications in patients is less, and it has high safety.

Explosion Mechanism of Lubricating Oil Droplets in High-Temperature and High-Pressure Combustion Environments

Lubricating oil-induced pre-ignition is a critical issue that requires attention in downsized gasoline engines and marine low-speed two-stroke natural gas engines. As a result, the ignition behavior of lubricating oil at high temperatures and pressures has been extensively studied. In some cases, when studying the ignition of oil droplets using a rapid compression machine, an explosion-like behavior of the oil droplets is observed, producing a soot cloud that can spread throughout the combustion chamber, especially when the ignition delay time of the ambient gas is short. To gain detailed insights into the mechanism of oil droplet explosion, the explosion process under initial pressures from 13 to 31 bar and temperatures from 700 to 1600 K was visualized using high-speed photography and microphotography on a rapid compression machine. The effects of temperature and shock waves were experimentally investigated, and droplet deformation after shock wave impact was calculated using a simple model. The results demonstrated that high temperature does not have a significant effect on droplet explosion under the conditions studied in this paper. The shock wave impact is the primary cause of the droplet’s explosion.

Physics of flame evolution following spontaneously combusting hydrogen emerging from a tube into the unconfined space

Unexpected self-ignition flame resulting from accidental release of pressurized hydrogen can induce a jet flame after it flows into the unconfined space. The flame evolution in the near-field region of the tube exit is important for the formation of jet flame. This paper presents a study on the physics for the evolution of spontaneously combusting hydrogen flame near the tube exit. Effects of release pressure and tube length are explored. Results show that the flame evolution is controlled by both the shock wave and vortex formed in the near-field region around the nozzle. Although two different types of flame evolution can be formed, both of them undergo the same four stages: initial flame, flame under the effect of shock wave, flame under the effect of vortex and stable combustion. The initial location of the vortex in the two types is different, which is the reason for the presence or absence of the flame separation phenomenon. If the vortex is formed inside the flame, flame separation is induced. In addition, two types of flame can transform into each other depending on the tube length. A hybrid flame can be clearly identified in the transition region in which the tube length varies from 300 mm to 700 mm. It has also been found that the flame in the transition region has features of both types and is easy to be extinguished.

Numerical Simulation of the Effect of Catalyst on Explosives Detonation Performance

Previous studies on the effect of the blast shock wave are mainly based on experiments. However, due to the extremely short duration of the blast shock, usually within several dozen milliseconds, the blast shock wave will have gone from peak to zero, causing a significant impact on the accuracy of experimental results. In recent years, numerical simulation has become an important method to study the effect of the blast. To study the influence of catalysts on the combustion performance of explosives, this paper intends to study the effect of catalysts on the combustion and explosion performance of pyrotechnic explosives. ANSYS workbench finite element analysis software was used to establish a pyrotechnic-rock blasting model to simulate the different effects produced by different catalysts during the combustion of explosives and compare their blasting effects. It is expected to obtain the preparation technology of higher performance nano-combustion catalysts, good performance nano-combustion catalyst system and its microstructure on the catalytic law of energy-containing materials, and to lay an important theoretical foundation for further development of new varieties of fire explosives with excellent comprehensive performance.

Experimental investigation on effect of gas/spray interactions on transient diesel spray behaviors

The ever-increasing rail pressure in diesel engines may cause the injection induced shock waves. In the present study, different gases (N2 and CO2) were used as the ambient mediums in order to understand the effect of shock waves induced by the high-speed jets on the near-field spray penetration. The tests were carried out in an optically-accessible constant volume vessel and a single-hole diesel injector was used. The injection pressure ( Pinj) ranged from 80 to 150 MPa and the ambient density ( ρambient) are 11.25, 22.52, and 33.81 kg/m3, respectively. Schlieren imaging was used to capture the shock waves ahead of the sprays with a frame speed of 100,000 fps and high-speed imaging was used to capture the spray penetration evolution with a frame speed of 300,000 fps in order to provide sufficient high temporal and spatial resolutions of the spray development. Shock waves can be observed under CO2 atmosphere over all the tested conditions and almost invisible under N2 atmosphere. The timings of occurrence and detachment of the shock waves are advanced with the increase in ρambient, but less sensitivity to Pinj. The difference in penetration lengths for N2 and CO2 atmosphere are not consistent as Pinj and ρambient varied, indicating the complicated role of shock waves in influencing the spray behaviors. Several mechanisms for the generation of shock waves were discussed, as well the physical meaning of the timing to the peak velocity of the spray tip with breakup time.

Experimental investigation on high-pressure methane jet characteristic single-hole injector

High-pressure gas direct injection (DI) technology benefits engines with high efficiency and clean emissions, and the gas jet process causes crucial effects especially inside an mm-size space. This study presents an investigation on the high-pressure methane jet characteristics from a single-hole injector by analysing jet performance parameters including jet impact force, gas jet impulse, and jet mass flow rate. The results show that the methane jet exhibited a two-zone behaviour along the jet direction in the spatial dimension induced by high-speed jet flow from the nozzle: zone 1 near the nozzle—the jet impact force and jet impulse increased consistently except for a fluctuation due to shock wave effects induced by the sonic jet and no entrainment occurs, and zone II farther away from the nozzle—the jet impact force and jet impulse became stable when the shock wave effects became weak and the jet impulse was conserved with a linear conservation boundary. The Mach disk height was exactly the turning point of two zones. Moreover, the methane jet parameters, such as the methane jet mass flow rate, jet initial jet impact force, jet impulse, and Reynolds number had a monotonous and linearly increasing correlation with injection pressure.

Interaction of a single bubble and an elastic plate: Influence of the standoff distance

The objective of this study was to investigate the coupled dynamics of a collapsing bubble and the motion of a nearby elastic plate at different initial distances. This was achieved using a combination of experimental and computational models. In the experiments, high-speed photography was used to record the temporal and spatial evolution of the collapse of a single bubble near an elastic boundary under normalized standoff distances γ ranging from 1.0 to 3.3. Digital image correlation was used to synchronously record the motion of the elastic plate. For the numerical simulations, taking the fluid compressibility and boundary motion into account, the immersed-boundary method was introduced to simulate the interaction between the elastic plate and bubble collapse. The results show that, with different initial distances, the dynamic behaviors of the bubble, including oscillation time, impact mode, and energy conversion, are different, and this is caused by the elastic rebound of the plate. In addition, the direction and amplitude of the deformation of the elastic plate are also influenced by the impact effects during bubble oscillation and rebound. The combined form of these impact behaviors changes with initial distance, and there are three typical impact patterns: the shock-wave effect, jet-effect, and hybrid shock-wave and jet-effect modes. In particular, when γ &amp;lt; 1.5, the jet effect and hybrid impact forms, which are dominated by the high-speed jet, can result in asymmetric deformation and cause greater local damage to the elastic plate. Finally, we summarize the combined mechanisms that govern the impact of a collapsing bubble on an elastic plate.

Vulnerability assessment of storage tanks exposed to simultaneous fire and explosion hazards

• Vulnerability of storage tanks under simultaneous fire and explosion is addressed. • A quantitative method for vulnerability assessment is developed. • The effect of pre-fire exposure on the scaled safety distance of tanks is analyzed. • The method can be used for rapid quantitative risk assessment of domino effects. Storage tanks are vulnerable to the synergistic effect of fire heat radiation and explosion shock wave during domino accidents in hydrocarbon storage tank farms. The available vulnerability analysis model for estimating the damage probability of secondary targets subjected to accident escalation vectors is a critical step for quantitative risk assessment of domino effects. However, due to the complexity of combined loadings, research on the vulnerability assessment of atmospheric storage tanks involved in the synergistic effect of fire and explosion is limited. This study aims to establish a method for quantitative evaluation of the vulnerability of storage tanks exposed to simultaneous fire and explosion hazards. The developed method addresses the coupling effect of high temperature caused by fire and instantaneous strong impulse induced by explosion on the damage probability of atmospheric storage tanks. Application of the proposed method to different cases highlight that pre-fire exposure has significant effects on the damage probability and the scaled safety distance of the tank under subsequent explosion load. The proposed approach can be used for rapid quantitative risk assessment of domino effect involving the synergistic impacts of fire and explosion.

Effects of obstacles inside the tube on initial self-ignition of high-pressure hydrogen release through a tube

The safe application of hydrogen has attracted increased attention. In particular, fire and explosion disasters may be induced by self-ignition during high-pressure hydrogen leakage. This study experimentally investigates the effect of obstacles on initial self-ignition when high-pressure hydrogen is suddenly released. High-pressure hydrogen release experiments are performed at burst pressures of 2–8 MPa. The hydrogen flame inside the tube is captured by a high-speed video camera and light sensors, and shock wave variations are measured by pressure transducers. The results show that the presence of obstacles inside the tube significantly affects shock wave flow. It is found in this study that obstacles decrease the minimum burst pressure needed for self-ignition and self-ignition is prone to occur in the vicinity of obstacles. The influence of obstacles on the initial ignition process are different at different self-ignition locations. On the one hand, the reflected shock wave originating from obstacles is the main reason for the promotion of self-ignition upstream of obstacles. On the other hand, the formation of a hydrogen/air mixture under the effect of turbulent flow and multi-dimensional shock waves leads to self-ignition downstream of obstacles. Meanwhile, the presence of obstacles before the initial ignition location (Lin) shortens the distance between the ignition location and the burst disk and significantly accelerates the occurrence of initial self-ignition. Obstacles participate in the self-ignition process earlier when they are placed closer to the burst disk. However, obstacles after the initial ignition location (Lin) show no effect on the initial ignition process. The results can guide the safe use of high-pressure hydrogen.

ОЦЕНКА ЭФФЕКТИВНОСТИ ИНТЕРВАЛЬНОГО РЕГУЛИРОВАНИЯ ДВИЖЕНИЯ ПОЕЗДОВ

The paper analyses the purpose, main characteristics and extent of implementation of interval control, as well as experience in assessing its efficiency. Problems associated with the introduction of interval control, in particular the «shockwave effect» arising from the densification of train flows and exacerbating the cumulative chain reaction, have been investigated. The directions for further research in the evaluation of the efficiency of interval control were determined: modelling of the operation of specific sections and stations, analysis of throughput under conditions of digital radio communication failures, development of solutions oriented towards the seamless transport process, correction of documentation, evaluation of the efficiency of interval control on single-track lines. The structure of a decision support system for the development of interval control on single-track lines is proposed.

Effects of Cavitation from Extracorporeal Shock Wave Combined with Sulfur Hexafluoride Microbubble on Myocardial Ultrastructure in Rats.

In the present study, the effects of extracorporeal cardiac shock waves combined with different concentrations of sulfur hexafluoride ultrasound microbubbles on myocardial ultrastructure in rats were observed. Thirty-six rats were randomly divided into 6 groups: control group (N), extracorporeal cardiac shock wave group, and combined group, i.e., extracorporeal cardiac shock wave combined with different concentrations of sulfur hexafluoride microbubble (0.225 mL/kg/min, 0.45 mL/kg/min, 0.9 mL/kg/min, 1.8 mL/kg/min). The combination of extracorporeal cardiac shock wave combined with sulfur hexafluoride microbubbles of different concentrations had no significant effect on hemodynamic indexes and left ventricular function in rats. There were significant differences in cardiac troponin I (cTnI) and nitricoxide among different groups. Histopathology showed that inflammatory cells infiltrated in the shock wave+microbubble 0.9 and shock wave+microbubble 1.8 groups. The myocardial ultrastructural injury score of shock wave+microbubble1.8 group was significantly higher than that of the N group, shock wave group, shock wave+microbubble 0.225 group, and shock wave+microbubble 0.45 group. The score of shock wave+microbubble 0.9 group was higher than that of the control group (P=.009). Western blot results showed that the expression of vascular endothelial growth factor and endothelial nitricoxide synthase (eNOS) protein in the rats treated with extracorporeal cardiac shock wave combined with sulfur hexafluoride microbubbles of different concentrations was higher than that in the N group and shock wave group, with shock wave+microbubble 0.45 group having the strongest expression. Myocardial ultrastructure damage occurs when high concentrations of sulfur hexafluoride microbubbles are present, but a proper concentration of sulfur hexafluoride microbubbles could promote the cavitation effect of extracorporeal cardiac shock waves. Thus combination therapy may become a new paradigm in coronary heart disease, especially contributing to the treatment of refractory angina. Combination therapy may change coronary heart disease treatment, especially for refractory angina.

Extracorporeal Shock Wave in Combination with Arthroscopy for Calcified Supraspinatus Tendonitis

Objective: Exploring the therapeutic effect of extracorporeal shockwave combined with Arthroscopic Surgery on calcified supraspinatus tendinitis. Materials and Methods: Sixty patients with calcific supraspinatus tendinitis who received treatment in our hospital from June 2022 to June 2023 were randomly divided into two groups. All patients had disease lasting more than 6 months. The control group received extracorporeal shockwave therapy (ESWT), while the observation group, after undergoing arthroscopic debridement of calcific deposits in the joint, began receiving the same ESWT as the control group after 2 weeks. The differences in Visual Analog Scale (VAS) score, University of California at Los Angeles (UCLA) score, and Constant–Murley score between the two groups before and after treatment were recorded and compared. Results: Before treatment, there was no significant difference in VAS score, UCLA score, and Constant–Murley Scale (CMS) score between the two groups of patients (P &gt; 0.05); compared with before treatment, both groups of patients showed a significant decrease in VAS scores after 1 and 2 months of treatment (P &lt; 0.05). After 1 and 2 months of treatment, the VAS scores of the observation group were significantly lower than the ones of the control group (P &lt; 0.05). Compared with before treatment, the UCLA score and CMS score of both groups of patients significantly increased after 1 and 2 months of treatment (P &lt; 0.05). After 1 and 2 months of treatment, the UCLA score and CMS score of the observation group were significantly higher than those of the control group (P &lt; 0.05). Conclusion: The combination of extracorporeal shockwave and arthroscopy has a significant therapeutic effect on calcified supraspinatus tendinitis, helping to improve shoulder joint function and effectively alleviate pain in patients. Keywords: Extracorporeal shockwave, Arthroscopy, Calcifying supraspinatus tendinitis, Shoulder joint function, Pain.

Cyanide Molecular Laser-Induced Plasma Spectroscopy

This work communicates recent measurements of CN in laser-induced plasma. The main goals and objectives comprise (a) exploring CN measurement using optical emission spectroscopy in optical breakdown plasma; (b) determining the effects of laser-induced shockwave for time delays of the order of 1 μs; (c) evaluating the spatial distribution of CN signals; (d) inferring CN temperature distribution; and (e) associating recorded shadowgraphs with laser-spectroscopy results. Q-switched, 150 mJ, 6 ns pulsed Nd:YAG laser radiation at the fundamental wavelength of 1064 nm is used to generate micro-plasma in a gas mixture with ultra-high purity nitrogen and research grade carbon dioxide. The CO2 to N2 molar ratio is 1 to 1 for the gaseous mixture near atmospheric pressure flowing through the chamber. Optical emissions are dispersed by a 0.64-m Czerny-Turner spectrometer and an intensified charge-coupled device records the data along the wavelength and slit dimensions. The analysis utilizes Abel integral inversion techniques for determination of spatiotemporal profiles.

Formation of Shock-Wave Flow during Nanosecond Discharge Localization in Unsteady Flow in a Channel with Obstacles

The results of studies of the effect of volume and surface pulse discharges on high-speed gas flow in a rectangular shock-tube channel with a change in the profile (obstacle on the lower wall) are given. A single nanosecond surface discharge or a discharge with preionization induced by the plasma electrodes (combined discharge) was initiated in flow downstream of the shock wave with the Mach numbers Ms = 3.2–3.4. The obstacle determines the distribution of the parameters of flow past the obstacle and the pulse discharge plasma redistribution. The density fields of gas dynamic flow under the experimental conditions are obtained and compared with the discharge plasma distribution. It is shown that the shock-wave effect of the discharge on flow behind the obstacle continued from 25 to 70 μs.