Role of non-circular jets in the performance of Hartmann whistles

Thomas, Sonu K.; Narava, Venkata S.R.; Srinivasan, K.

doi:10.1016/j.apacoust.2022.108736

Cited by 2 publications

(3 citation statements)

References 29 publications

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“…The Hartmann-Sprenger energy separation effect is based on the principle of gasdynamic resonance and thermal energy separation through nonlinear self-oscillating gas pressure fluctuations in a plugged cavity, which arise as a result of a supersonic gas flow around it. Temperature separation occurs due to the cumulative supply of heat to the gas volume that becomes trapped the resonator's dead end [34], which is formed as a result of the dissipative processes of affecting this volume through periodic shock waves propagating inside the resonator [35,36], as well as due to gas friction against its walls [37]. This ensures the attainment of high temperatures and a low cooling capacity, which is additionally explained by the essence of the flow mixing mechanism [38].…”

Section: Existing Developmentsmentioning

confidence: 99%

Hartmann–Sprenger Energy Separation Effect for the Quasi-Isothermal Pressure Reduction of Natural Gas: Feasibility Analysis and Numerical Simulation

Belousov,

Lushpeev,

Sokolov

et al. 2024

Energies

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The present paper provides a brief overview of the existing methods for energy separation and an analysis of the possibility of the practical application of the Hartmann–Sprenger effect to provide quasi-isothermal pressure reduction of natural gas at the facilities within a gas transmission system. The recommendations of external authors are analyzed. A variant of a quasi-isothermal pressure regulator is proposed, which assumes the mixing of flows after energy separation. Using a numerical simulation of gas dynamics, it is demonstrated that the position of the resonators can be determined on the basis of calculations of the structure of the underexpanded jet without taking into account the resonator and, accordingly, without the need for time-consuming calculations of the dynamics of the processes. Based on the results of simulating the gas dynamics of two nozzle–resonator pairs installed in a single flow housing, it is shown that, in order to optimize the regulator length, the width of the passage between the two nearest resonators should be greater than or equal to the sum of diameters of the critical sections of the nozzles. Numerical vibroacoustic analysis demonstrated that the most dangerous part of the resonator is the frequency of its natural oscillations.

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Section: Existing Developmentsmentioning

confidence: 99%

Hartmann–Sprenger Energy Separation Effect for the Quasi-Isothermal Pressure Reduction of Natural Gas: Feasibility Analysis and Numerical Simulation

Belousov,

Lushpeev,

Sokolov

et al. 2024

Energies

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“…Development is also in progress to use the Hartmann tube fluidic actuators for high-speed flow control (Kastner and Samimy [17]). Thomas, et al [18] studied the role of non-circular jets in the performance of Hartmann whistles. But this study focuses mainly on the orifice effect on the sound level and not on the mechanism responsible for the nature of the whistle from the cavity.…”

Section: Literature Reviewmentioning

confidence: 99%

“…Recently Solomon et al [19] reported controlled mixing of fuel with fast-moving air is a challenging physical problem relevant to hypersonic systems. With a focus on improving mixing at extreme flow conditions, this paper presents a fundamental study of a novel, high-speed, pulsed-coflow system integrated with ultrahigh-frequency actuators (11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

Section: Literature Reviewmentioning

confidence: 99%

Experimental studies on the Hartmann tube

Rathakrishnan

2024

Aeronaut. j.

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The effect of tube depth, the separation distance between the tube and nozzle exit, and the nozzle pressure ratio on the characteristics of the flow coming out of the Hartmann tube was studied experimentally. The configuration used in this work consists of an underexpanded sonic jet emanating from a convergent nozzle directed into a closed-ended cylindrical tube of the same diameter (D) as the nozzle exit. The nozzle was operated at two levels of underexpansion corresponding to nozzle pressure ratio (NPR) 3 and 5. The distance (S) from nozzle exit and tube inlet was varied from 0.4D to 4D. Discrete high-amplitude tones (the jet regurgitant, JRG) were produced, only at certain (periodic) intervals (near the shock-cell terminations) of spacing for NPR 3, while for NPR 5 the JRG tones are produced at all points beyond the first shock-cell. For locations other than these, high-frequency tones (screech mode) were observed. The connection between the jet structure and operating modes revealed that the location of standoff shock ahead of the tube with respect to the jet structure plays a dominant role in the observed ‘modes’ rather than the nozzle tube separation. The results reveal that the frequency response of longer tubes in JRG mode approaches their quarter wave frequencies. The high-frequency oscillations observed in the screech mode showed independency with cavity (pipe) depth, contrary to the available literature, the transition between ‘different modes’ oscillation is a function of cavity depth.

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Role of non-circular jets in the performance of Hartmann whistles

Cited by 2 publications

References 29 publications

Hartmann–Sprenger Energy Separation Effect for the Quasi-Isothermal Pressure Reduction of Natural Gas: Feasibility Analysis and Numerical Simulation

Hartmann–Sprenger Energy Separation Effect for the Quasi-Isothermal Pressure Reduction of Natural Gas: Feasibility Analysis and Numerical Simulation

Experimental studies on the Hartmann tube

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