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Diffusion-Drift Model of the Surface Glow Discharge in Supersonic Gas Flow 超音速气体流中表面辉光放电的扩散漂移模型
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602346
S. T. Surzhikov

Abstract

The two-dimensional electrogasdynamic problem of anomalous glow discharge on the surface of a sharp plate in supersonic flow of a perfect gas is solved using the system of Navier–Stokes equations to describe thermogasdynamic processes in the boundary layer and the two-temperature two-fluid diffusion-drift model of gas-discharge plasma to determine the electrodynamic structure of the discharge. The near-electrode regions of space charge and the external electrical circuit consisting of a power source and an ohmic resistance are taken into account. The influence of the magnetic field which is transverse to gas flow and has the induction of up to 0.03 T on the structure of boundary layer and glow discharge is studied. The electrogasdynamic structure of anomalous near-surface discharges is studied numerically over a wide range of gas flow velocities (M = 5–20), the free-stream pressures (p = 0.6–5 Torr), the electrode voltages, and the electric currents through the discharges. The electrodynamic structure of the gas-plasma flow near the electrodes and the effect of the glow discharge on the pressure and temperature distributions along the surface of the plate are also studied.

摘要 利用纳维-斯托克斯方程组描述边界层的热气动力学过程,并利用气体放电等离子体的双温双流体扩散漂移模型确定放电的电动力学结构,求解了完美气体超音速流中尖板表面异常辉光放电的二维电-气动力学问题。空间电荷的近电极区域以及由电源和欧姆电阻组成的外部电路都被考虑在内。研究了横向于气体流且感应强度高达 0.03 T 的磁场对边界层和辉光放电结构的影响。在很大的气体流速(M = 5-20)、自由流压力(p = 0.6-5 托)、电极电压和通过放电的电流范围内,对异常近表面放电的气体电动结构进行了数值研究。此外,还研究了电极附近气体等离子体流的电动结构以及辉光放电对沿板表面的压力和温度分布的影响。
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引用次数: 0
Diagnostics of the Ionization Processes in Hydrocarbon Flame with the Use of the Current–Voltage Characteristics 利用电流-电压特性诊断碳氢化合物火焰中的电离过程
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602322
V. A. Polyanskii, I. L. Pankrat’eva

Abstract

The possibility of estimating the ionization parameters of high-temperature gas mixtures formed as a result of combustion processes is considered on the basis of the current–voltage characteristics measured using electrodes that generate an external electric field in the media under consideration.

摘要 根据在所考虑的介质中产生外部电场的电极测得的电流-电压特性,考虑了估算燃烧过程中形成的高温气体混合物电离参数的可能性。
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引用次数: 0
Modeling of the Unsteady Aerodynamic Characteristics of the NACA 0015 Airfoil from the Data of Numerical Calculations of the Flow 根据流动数值计算数据建立 NACA 0015 机翼非稳态空气动力特性模型
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602929
K. A. Abramova, D. A. Alieva, V. G. Sudakov, A. N. Khrabrov

Abstract

The possible application of the results of numerical modeling in developing an approximate phenomenological mathematical aerodynamic model applicable in solving the problems of dynamics is studied with reference to the example of the unsteady flow past the NACA 0015 airfoil oscillating in the angle of attack at different frequencies, amplitudes, and mean angles of attack. For this purpose, the Reynolds equations are solved in both steady and unsteady formulations, together with the k–ω SST turbulence model. The results of the calculations are validated by means of comparing them with the experimental data. The model of the normal force and the longitudinal moment formulated within the framework of an approach introducing an internal dynamic variable is identified according to the data of calculations. The results of the modeling are compared with the numerical and experimental data. The comparison with the conventional approach to the modeling based on the linear unsteady model with the use of dynamic derivatives is also carried out.

摘要 以 NACA 0015 机翼上以不同频率、振幅和平均攻角摆动的非稳态流为例,研究了数值建模结果在开发适用于解决动力学问题的近似现象数学空气动力学模型中的可能应用。为此,以稳定和非稳定两种形式求解了雷诺方程以及 k-ω SST 湍流模型。计算结果通过与实验数据的比较得到了验证。根据计算数据,确定了在引入内部动态变量的方法框架内制定的法向力和纵向力矩模型。建模结果与数值和实验数据进行了比较。此外,还与基于线性非稳态模型并使用动态导数的传统建模方法进行了比较。
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引用次数: 0
The Diffusion Stability of an Externally Driven Cavitation Bubble in Micro-Confinement 微凝固中外部驱动空化泡的扩散稳定性
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602413
K. V. Leonov, I. Sh. Akhatov

Abstract

The diffusion stability of a single cavitation bubble in a spherical liquid cell surrounded by an infinite elastic solid is considered. The time-periodic pressure in the solid far away from the liquid cell is used as an external driving, which initiates bubble oscillations along with the gas diffusion process in the bubble-in-cell system. The work is based on the engineering approximation according to which the bubble growth/reduction is considered on average, assuming that during the period of the external driving the mass of gas in the bubble does not noticeably change. This theory predicts the existence of stably oscillating bubbles in confined liquid undergoing an external driving force. Three possible diffusion regimes are revealed: 1) total bubble dissolution, 2) partial bubble dissolution, and 3) partial bubble growth, where the last two regimes provide the diffusion stability in the bubble-in-cell system. The parametric study of the influence of the gas concentration dissolved in the liquid on the resulting stable bubble size is conducted. The obtained results are compared with the results for the case of the stable bubble oscillations in the pressure sound field in a bulk (infinite) liquid. The theoretical findings of the present study can be used for improvement of the modern applications of ultrasound technology.

摘要 研究了被无限弹性固体包围的球形液胞中单个空化气泡的扩散稳定性。远离液胞的固体中的时间周期性压力被用作外部驱动力,它与气泡-液胞系统中的气体扩散过程一起引发气泡振荡。这项研究基于工程近似方法,假定在外部驱动期间,气泡中的气体质量不会发生明显变化,气泡的增长/减少按平均值考虑。该理论预言了在密闭液体中,在外部驱动力作用下存在稳定振荡的气泡。该理论揭示了三种可能的扩散机制:1) 全部气泡溶解;2) 部分气泡溶解;3) 部分气泡增长。对溶解在液体中的气体浓度对产生的稳定气泡大小的影响进行了参数研究。研究结果与在体积液体(无限大)压力声场中稳定气泡振荡的结果进行了比较。本研究的理论发现可用于改进超声波技术的现代应用。
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引用次数: 0
Oscillations of a Fluid in a Circular Cylinder with Bottom Elevation 底部隆起的圆柱中的流体振荡
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602486
S. V. Nesterov, V. A. Kalinichenko

Abstract

The problem of standing waves in a circular cylindrical vessel with an elevation on the bottom is formulated and numerically solved in the long wave approximation using an accelerated convergence algorithm. As a result of the calculations, the natural frequency of the fundamental wave mode is determined with a high accuracy. To compare the theoretical results, new experimental data on the excitation of standing surface gravity waves in a circular cylindrical vessel with parabolic and conical elevations at the bottom are presented. It is shown that the calculated and measured natural frequencies of the fundamental wave mode in vessels with the profiled bottom coincide between themselves.

摘要 在长波近似中,采用加速收敛算法对底部有高程的圆柱形圆形容器中的驻波问题进行了表述和数值求解。计算结果高精度地确定了基波模式的固有频率。为了比较理论结果,介绍了在底部有抛物线和锥形隆起的圆柱形圆形容器中激发驻面重力波的新实验数据。实验结果表明,在底部带有型面的容器中,基波模式的计算固有频率和测量固有频率是一致的。
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引用次数: 0
Analysis of the Flow Structure in a Supersonic Channel with Cavity 带空腔超音速通道中的流动结构分析
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-04-04 DOI: 10.1134/s0015462823602772
R. K. Seleznev

Abstract

The results of numerical study of supersonic flow in a channel with cavity are given. The calculated oscillation spectra are analyzed using the fast Fourier transform. Two types of oscillatory modes can be distinguished in the resulting periodic self-oscillatory regime. The first type of the modes corresponds to acoustic vibrations caused by the passage of sound waves along the cavity and calculated using the modified Rossiter formula. The second type of the modes corresponds to the frequencies of flow-rate oscillations caused by mass transfer between the cavity and the external flow. It is shown that the flow structure is modified when fuel is supplied in front of the cavity. Active combustion occurs in the layer of mixing fuel and oxygen from air. The flow pattern demonstrates the onset of Kelvin–Helmholtz instability on the interface between the main flow and the reacted gas. It is shown that an increase in the supplied fuel pressure leads to a decrease in the oscillation frequency and an increase in the characteristic size of oscillations.

摘要 本文给出了带空腔通道中超音速流动的数值研究结果。利用快速傅立叶变换分析了计算出的振荡频谱。在由此产生的周期性自振荡机制中,可以区分出两种振荡模式。第一类模式对应于声波沿空腔通过时引起的声学振动,使用修正的 Rossiter 公式计算。第二类模式对应于空腔和外部气流之间质量传递引起的流速振荡频率。研究表明,当在空腔前方提供燃料时,流动结构会发生改变。在燃料和空气中的氧气混合层中会发生主动燃烧。流动模式表明,在主气流和反应气体之间的界面上出现了开尔文-赫尔姆霍兹不稳定性。结果表明,供应燃料压力的增加会导致振荡频率的降低和振荡特征尺寸的增加。
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引用次数: 0
On the Method for Estimating the Integral Characteristics of a Generic Scramjet with an Integrated Propulsion System 论估算具有综合推进系统的通用 Scramjet 整体特性的方法
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-03-24 DOI: 10.1134/s0015462823602607
R. K. Seleznev

Abstract

This paper outlines a methodology for assessing the integral characteristics of a generic scramjet with an integrated propulsion system (PS). The specific impulse and heat flows in the PS for X-43 and X-51 scramjets are calculated. The results obtained are in good agreement with the estimates of other authors (in the speed range 5 < M < 10), as well as with the known graphs of the specific impulse dependence for various types of engines depending on the flight Mach number and the type of fuel used.

摘要 本文概述了一种评估带有集成推进系统(PS)的通用扰流喷气机整体特性的方法。计算了 X-43 和 X-51 加力燃烧喷气发动机的比冲和 PS 中的热流。所获得的结果与其他作者的估计值(速度范围为 5 < M < 10)以及各种类型发动机(取决于飞行马赫数和所使用的燃料类型)的比冲依赖性已知曲线图非常一致。
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引用次数: 0
Ignition of a Combustible Gas Mixture by a Microwave Subcritical Streamer Discharge in a High-Speed Flow 微波亚临界流束在高速气流中点燃可燃混合气体
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-03-24 DOI: 10.1134/s0015462823602620
K. N. Volkov, P. V. Bulat, L. P. Grachev, I. I. Esakov, A. A. Ravaev

Abstract

The possibilities of igniting a combustible mixture in a high-speed flow using a microwave streamer discharge are considered. The results of experimental studies of the streamer discharge structure at various pressures are presented. To quantitatively characterize the intensity of combustion of fuel ignited by a microwave discharge, pressure and temperature measurements are used in various sections of the jet in the discharge wake. The results obtained demonstrate the possibility of igniting a model combustible mixture when propane or its mixture with air is sup-plied to the discharge region. The main physical mechanisms responsible for heating the discharge plasma to the ignition temperature of the combustible mixture and their characteristic time scales are revealed. The change in the dimensions of the combustion zone with a decrease in the initial proportion of propane in the mixture is discussed. The minimum duration and minimum level of microwave radiation required to ignite a model combustible mixture under various conditions are determined.

摘要 研究了利用微波流束放电点燃高速气流中可燃混合物的可能性。本文介绍了在不同压力下流线型放电结构的实验研究结果。为了定量描述微波放电点燃燃料的燃烧强度,在放电尾流的不同射流段使用了压力和温度测量方法。测量结果表明,当丙烷或其与空气的混合物被注入放电区域时,有可能点燃模型可燃混合物。揭示了将放电等离子体加热到可燃混合物点火温度的主要物理机制及其特征时间尺度。讨论了随着混合物中丙烷初始比例的降低,燃烧区尺寸的变化。确定了在各种条件下点燃模型可燃混合物所需的最短时间和最低微波辐射水平。
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引用次数: 0
Research on the Possibilities of Increasing Stagnation Pressure in a High-Speed Flow 关于提高高速流动中停滞压力可能性的研究
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-03-24 DOI: 10.1134/s0015462823602565
D. E. Khazov

Abstract

Stagnation pressure is usually increased by so-called machine methods—various compressors that operate by supplying mechanical energy to the flow. This paper considers a method for increasing the stagnation pressure based on the thermal influence on the flow (heat removal). The influence of various factors on the degree of the increase in stagnation pressure for a channel flow under only thermal influence is studied. This paper considers various flow cooling methods. It is shown that evaporative cooling is the most effective in terms of increasing the stagnation pressure. A review of publications on the use of evaporative cooling to increase stagnation pressure is provided. Based on a one-dimensional model of an evaporative cooling device, it is shown that it is possible to increase stagnation pressure by a factor of 1.25 at supersonic inlet velocities.

摘要 通常通过所谓的机器方法来增加停滞压力,即通过向流动提供机械能来运行的各种压缩机。本文探讨了一种基于对流动的热影响(散热)来增加停滞压力的方法。本文研究了各种因素对仅受热影响的通道流动的停滞压力增加程度的影响。本文考虑了各种流动冷却方法。结果表明,就增加滞流压力而言,蒸发冷却最为有效。本文对利用蒸发冷却增加滞流压力的出版物进行了综述。根据蒸发冷却装置的一维模型,可以看出在超音速入口速度下,停滞压力可以提高 1.25 倍。
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引用次数: 0
Analytical Representations of Far Fields of Internal Gravity Waves from Local and Nonlocal Perturbation Sources 来自局部和非局部扰动源的内引力波远场的分析表征
IF 0.9 4区 工程技术 Q3 Chemical Engineering Pub Date : 2024-03-24 DOI: 10.1134/s0015462823603182
V. V. Bulatov

Abstract

In this work, the analytical representations of far fields of internal gravity waves from local and nonlocal perturbation sources in a layer of arbitrarily stratified medium of finite depth are considered. The internal criteria of applicability of various asymptotic representations are formulated that provide a predetermined accuracy of asymptotic calculations of far wave fields. It is shown that for elongated perturbation sources, in the case when the characteristic dimensions of the source are comparable to the width of the first pulse of the wave, the corresponding convolution provides the maximum values of the elevation field of internal gravity waves in the neighborhood of the wave front and, oscillating, rapidly decays with distance from it, because the neighboring half-waves mitigate each other far from the wave front.

摘要 本研究考虑了有限深度任意分层介质层中来自局部和非局部扰动源的内部重力波远场的分析表示。提出了各种渐近表示法适用性的内部标准,为远波场的渐近计算提供了预定精度。结果表明,对于拉长的扰动源,当扰动源的特征尺寸与波的第一个脉冲宽度相当时,相应的卷积会提供波前附近内重力波仰角场的最大值,并且随着波前距离的增加而迅速衰减,因为相邻的半波会在远离波前的地方相互减弱。
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引用次数: 0
期刊
Fluid Dynamics
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