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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Wed, 28 Feb 2024 00:09:42 GMT2024-02-28T00:09:42ZAn unexpected balance between outer Rayleigh streaming sources
http://hdl.handle.net/10985/18011
An unexpected balance between outer Rayleigh streaming sources
BALTEAN-CARLÈS, Diana; DARU, Virginie; WEISMAN, Catherine; TABAKOVA, S.; BAILLIET, Hélène
Acoustic streaming generated by a plane standing wave between two infinite plates or inside a cylindrical tube is considered, under the isentropic flow assumption. A two-dimensional analysis is performed in the linear case of slow streaming motion, based on analytical formal solutions of separate problems, each associated with a specific source term (Reynolds stress term). In order to obtain these analytical solutions, a necessary geometrical hypothesis is that (R/L)2 << 1, where R and L are the guide half-width (or radius) and length. The effect of the two source terms classically taken into account is quantified in order to derive the dependence of the maximum axial streaming velocity on the axis as a function of the ratio R/δν , where δν is the acoustic boundary layer thickness. The effect of two other source terms that are usually neglected, is then analysed. It is found that one of these terms can generate a counter-rotating streaming flow. While negligible for very narrow guides, this term can become important for some values of the aspect ratio L/R.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/180112019-01-01T00:00:00ZBALTEAN-CARLÈS, DianaDARU, VirginieWEISMAN, CatherineTABAKOVA, S.BAILLIET, HélèneAcoustic streaming generated by a plane standing wave between two infinite plates or inside a cylindrical tube is considered, under the isentropic flow assumption. A two-dimensional analysis is performed in the linear case of slow streaming motion, based on analytical formal solutions of separate problems, each associated with a specific source term (Reynolds stress term). In order to obtain these analytical solutions, a necessary geometrical hypothesis is that (R/L)2 << 1, where R and L are the guide half-width (or radius) and length. The effect of the two source terms classically taken into account is quantified in order to derive the dependence of the maximum axial streaming velocity on the axis as a function of the ratio R/δν , where δν is the acoustic boundary layer thickness. The effect of two other source terms that are usually neglected, is then analysed. It is found that one of these terms can generate a counter-rotating streaming flow. While negligible for very narrow guides, this term can become important for some values of the aspect ratio L/R.Inertial effects on acoustic Rayleigh streaming flow: Transient and established regimes
http://hdl.handle.net/10985/17478
Inertial effects on acoustic Rayleigh streaming flow: Transient and established regimes
DARU, Virginie; WEISMAN, Catherine; BALTEAN-CARLÈS, Diana; REYT, Ida; BAILLIET, Hélène
The effect of inertia on Rayleigh streaming generated inside a cylindrical resonator where a mono-frequency standing wave is imposed, is investigated numerically and experimentally. To this effect, time evolutions of streaming cells in the near wall region and in the resonator core are analyzed. An analogy with the lid-driven cavity in a cylindrical geometry is presented in order to analyze the physical meanings of the characteristic times. Inertial effects on the established streaming flow pattern are then investigated numerically using a code solving the time averaged Navier–Stokes compressible equations, where a mono-frequency acoustic flow field is used to compute the source terms. It is shown that inertia of streaming cannot be considered as the leading phenomenon to explain the mutation of streaming at high acoustic levels.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/174782017-01-01T00:00:00ZDARU, VirginieWEISMAN, CatherineBALTEAN-CARLÈS, DianaREYT, IdaBAILLIET, HélèneThe effect of inertia on Rayleigh streaming generated inside a cylindrical resonator where a mono-frequency standing wave is imposed, is investigated numerically and experimentally. To this effect, time evolutions of streaming cells in the near wall region and in the resonator core are analyzed. An analogy with the lid-driven cavity in a cylindrical geometry is presented in order to analyze the physical meanings of the characteristic times. Inertial effects on the established streaming flow pattern are then investigated numerically using a code solving the time averaged Navier–Stokes compressible equations, where a mono-frequency acoustic flow field is used to compute the source terms. It is shown that inertia of streaming cannot be considered as the leading phenomenon to explain the mutation of streaming at high acoustic levels.A numerical study of the coupling between Rayleigh streaming and heat transfer at high acoustic level
http://hdl.handle.net/10985/21439
A numerical study of the coupling between Rayleigh streaming and heat transfer at high acoustic level
DARU, Virginie; WEISMAN, Catherine; BALTEAN-CARLÈS, Diana; BAILLIET, Hélène
coupling between thermal effects and Rayleigh streaming in a standing wave guide at high acoustic levels is analyzed numerically. The approach is guided by the recent analytical study, showing that reverse streaming cells can form if the nonlinear Reynolds number exceeds a value depending on the wave frequency and thermophysical properties of the fluid and solid wall. A numerical configuration is introduced to investigate the evolution of the streaming flow structure and the average temperature field at high acoustic levels. Special attention is given to inhibit the development of shock waves. The heat conduction is accounted for in the wall. As the acoustic level is increased, the average temperature field becomes stratified transversely. The simulations show the relevance of the criterion for characterizing the appearance of additional contrarotating streaming cells near the acoustic velocity antinodes. For higher acoustic levels, these additional cells evolve into increasingly large stagnant zones, where the streaming flow is of very small amplitude and the contours of temperature are stratified longitudinally. The overall outer streaming flow decreases. These results are consistent with previous experimental observations, showing that the intrinsic coupling between the thermal effects and acoustic streaming at high levels is very well described.
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/10985/214392021-01-01T00:00:00ZDARU, VirginieWEISMAN, CatherineBALTEAN-CARLÈS, DianaBAILLIET, Hélènecoupling between thermal effects and Rayleigh streaming in a standing wave guide at high acoustic levels is analyzed numerically. The approach is guided by the recent analytical study, showing that reverse streaming cells can form if the nonlinear Reynolds number exceeds a value depending on the wave frequency and thermophysical properties of the fluid and solid wall. A numerical configuration is introduced to investigate the evolution of the streaming flow structure and the average temperature field at high acoustic levels. Special attention is given to inhibit the development of shock waves. The heat conduction is accounted for in the wall. As the acoustic level is increased, the average temperature field becomes stratified transversely. The simulations show the relevance of the criterion for characterizing the appearance of additional contrarotating streaming cells near the acoustic velocity antinodes. For higher acoustic levels, these additional cells evolve into increasingly large stagnant zones, where the streaming flow is of very small amplitude and the contours of temperature are stratified longitudinally. The overall outer streaming flow decreases. These results are consistent with previous experimental observations, showing that the intrinsic coupling between the thermal effects and acoustic streaming at high levels is very well described.Acoustically induced thermal effects on Rayleigh streaming
http://hdl.handle.net/10985/21438
Acoustically induced thermal effects on Rayleigh streaming
DARU, Virginie; WEISMAN, Catherine; BALTEAN-CARLÈS, Diana; BAILLIET, Hélène
The present study focuses on acoustically induced thermal effects on Rayleigh streaming inside a resonator. Firstly, we consider the effect of the transverse (or wall-normal) mean temperature gradient on the acoustic streaming flow generated by a standing wave between two parallel plates. Analytical expressions for acoustic quantities are developed and used to express the sources of linear streaming. The influence of a transverse temperature variation on the streaming velocity is clearly identified through a term proportional to the temperature difference and to the square of the half-width of the guide. This term modifies the Rayleigh streaming pattern and may generate an additional vortex. On the other hand, the longitudinal (or wall-parallel) temperature difference is calculated as a cumulated effect of thermoacoustic heat transport in the fluid, heat conduction in the wall and heat convection of the air outside the resonator. At high acoustic levels, heat is significantly convected by the streaming flow and the resulting transverse temperature difference is proportional to the longitudinal temperature difference. Combining these expressions brings out a new criterion parameter for the nonlinear Reynolds number (ReNL) characterizing the transition in streaming patterns at high acoustic levels. This result explains previous experimental and numerical observations of the streaming flow dynamics at high acoustic amplitudes, under different temperature boundary conditions, and can provide a powerful prediction tool for streaming pattern transitions.
Fri, 01 Jan 2021 00:00:00 GMThttp://hdl.handle.net/10985/214382021-01-01T00:00:00ZDARU, VirginieWEISMAN, CatherineBALTEAN-CARLÈS, DianaBAILLIET, HélèneThe present study focuses on acoustically induced thermal effects on Rayleigh streaming inside a resonator. Firstly, we consider the effect of the transverse (or wall-normal) mean temperature gradient on the acoustic streaming flow generated by a standing wave between two parallel plates. Analytical expressions for acoustic quantities are developed and used to express the sources of linear streaming. The influence of a transverse temperature variation on the streaming velocity is clearly identified through a term proportional to the temperature difference and to the square of the half-width of the guide. This term modifies the Rayleigh streaming pattern and may generate an additional vortex. On the other hand, the longitudinal (or wall-parallel) temperature difference is calculated as a cumulated effect of thermoacoustic heat transport in the fluid, heat conduction in the wall and heat convection of the air outside the resonator. At high acoustic levels, heat is significantly convected by the streaming flow and the resulting transverse temperature difference is proportional to the longitudinal temperature difference. Combining these expressions brings out a new criterion parameter for the nonlinear Reynolds number (ReNL) characterizing the transition in streaming patterns at high acoustic levels. This result explains previous experimental and numerical observations of the streaming flow dynamics at high acoustic amplitudes, under different temperature boundary conditions, and can provide a powerful prediction tool for streaming pattern transitions.Acoustic and streaming velocity components in a resonant waveguide at high acoustic levels
http://hdl.handle.net/10985/17522
Acoustic and streaming velocity components in a resonant waveguide at high acoustic levels
DARU, Virginie; REYT, Ida; BAILLIET, Hélène; WEISMAN, Catherine; BALTEAN-CARLÈS, Diana
Rayleigh streaming is a steady flow generated by the interaction between an acoustic wave and a solid wall, generally assumed to be second order in a Mach number expansion. Acoustic streaming is well known in the case of a stationary plane wave at low amplitude: it has a half-wavelength spatial periodicity and the maximum axial streaming velocity is a quadratic function of the acoustic velocity amplitude at antinode. For higher acoustic levels, additional streaming cells have been observed. Results of laser Doppler velocimetry measurements are here compared to direct numerical simulations. The evolution of axial and radial velocity components for both acoustic and streaming velocities is studied from low to high acoustic amplitudes. Two streaming flow regimes are pointed out, the axial streaming dependency on acoustics going from quadratic to linear. The evolution of streaming flow is different for outer cells and for inner cells. Also, the hypothesis of radial streaming velocity being of second order in a Mach number expansion, is not valid at high amplitudes. The change of regime occurs when the radial streaming velocity amplitude becomes larger than the radial acoustic velocity amplitude, high levels being therefore characterized by nonlinear interaction of the different velocity components.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/175222017-01-01T00:00:00ZDARU, VirginieREYT, IdaBAILLIET, HélèneWEISMAN, CatherineBALTEAN-CARLÈS, DianaRayleigh streaming is a steady flow generated by the interaction between an acoustic wave and a solid wall, generally assumed to be second order in a Mach number expansion. Acoustic streaming is well known in the case of a stationary plane wave at low amplitude: it has a half-wavelength spatial periodicity and the maximum axial streaming velocity is a quadratic function of the acoustic velocity amplitude at antinode. For higher acoustic levels, additional streaming cells have been observed. Results of laser Doppler velocimetry measurements are here compared to direct numerical simulations. The evolution of axial and radial velocity components for both acoustic and streaming velocities is studied from low to high acoustic amplitudes. Two streaming flow regimes are pointed out, the axial streaming dependency on acoustics going from quadratic to linear. The evolution of streaming flow is different for outer cells and for inner cells. Also, the hypothesis of radial streaming velocity being of second order in a Mach number expansion, is not valid at high amplitudes. The change of regime occurs when the radial streaming velocity amplitude becomes larger than the radial acoustic velocity amplitude, high levels being therefore characterized by nonlinear interaction of the different velocity components.Fast acoustic streaming in standing waves : Generation of an additional outer streaming cell
http://hdl.handle.net/10985/8595
Fast acoustic streaming in standing waves : Generation of an additional outer streaming cell
REYT, Ida; BAILLIET, Hélène; MOREAU, Solène; VALIERE, Jean-Christophe; BALTEAN-CARLÈS, Diana; WEISMAN, Catherine; DARU, Virginie
Rayleigh streaming in a cylindrical acoustic standing waveguide is studied both experimentally and numerically for nonlinear Reynolds numbers from 1 to 30. Streaming velocity is measured by means of laser Doppler velocimetry in a cylindrical resonator filled with air at atmospheric pressure at high intensity sound levels. The compressible Navier-Stokes equations are solved numerically with high resolution finite difference schemes. The resonator is excited by shaking it along the axis at imposed frequency. Results of measurements and of numerical calculation are compared with results given in the literature and with each other. As expected, the axial streaming velocity measured and calculated agrees reasonably well with the slow streaming theory for small ReNL but deviates significantly from such predictions for fast streaming (ReNL > 1). Both experimental and numerical results show that when ReNL is increased, the center of the outer streaming cells are pushed toward the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/85952013-01-01T00:00:00ZREYT, IdaBAILLIET, HélèneMOREAU, SolèneVALIERE, Jean-ChristopheBALTEAN-CARLÈS, DianaWEISMAN, CatherineDARU, VirginieRayleigh streaming in a cylindrical acoustic standing waveguide is studied both experimentally and numerically for nonlinear Reynolds numbers from 1 to 30. Streaming velocity is measured by means of laser Doppler velocimetry in a cylindrical resonator filled with air at atmospheric pressure at high intensity sound levels. The compressible Navier-Stokes equations are solved numerically with high resolution finite difference schemes. The resonator is excited by shaking it along the axis at imposed frequency. Results of measurements and of numerical calculation are compared with results given in the literature and with each other. As expected, the axial streaming velocity measured and calculated agrees reasonably well with the slow streaming theory for small ReNL but deviates significantly from such predictions for fast streaming (ReNL > 1). Both experimental and numerical results show that when ReNL is increased, the center of the outer streaming cells are pushed toward the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes.