The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform

Christopher Tomkins - One of the best experts on this subject based on the ideXlab platform.

  • turbulent mixing in a richtmyer meshkov Fluid Layer after reshock velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.

  • Turbulent mixing in a Richtmyer–Meshkov Fluid Layer after reshock: velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.

O.m. El Mekki - One of the best experts on this subject based on the ideXlab platform.

  • On the thermal instability of a nonuniformly rotating Fluid Layer heated from below
    Solar Physics, 2001
    Co-Authors: O.m. El Mekki
    Abstract:

    The thermal instability both as stationary convection and overstability of a nonuniformly rotating Fluid Layer of vertical extent is considered. It is shown that in both types of instability the effect of the variation of the rate of rotation is to introduce a new branch to the marginal instability curves of uniform rotation which departs from them towards a zero of the Rayleigh number as the horizontal wavenumber approaches zero. The relevance to the solar interior is discussed.

Jeffrey W Jacobs - One of the best experts on this subject based on the ideXlab platform.

  • influence of initial conditions on the flow patterns of a shock accelerated thin Fluid Layer
    Physics of Fluids, 1994
    Co-Authors: John M Budzinski, R F Benjamin, Jeffrey W Jacobs
    Abstract:

    Previous observations of three flow patterns generated by shock acceleration of a thin perturbed, Fluid Layer are now correlated with asymmetries in the initial conditions. Using a different diagnostic (planar laser Rayleigh scattering) than the previous experiments, upstream mushrooms, downstream mushrooms, and sinuous patterns are still observed. For each experiment the initial perturbation amplitude on one side of the Layer can either be larger, smaller, or the same as the amplitude on the other side, as observed with two images per experiment, and these differences lead to the formation of the different patterns.

B J Balakumar - One of the best experts on this subject based on the ideXlab platform.

  • turbulent mixing in a richtmyer meshkov Fluid Layer after reshock velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.

  • Turbulent mixing in a Richtmyer–Meshkov Fluid Layer after reshock: velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.

Sridhar Balasubramanian - One of the best experts on this subject based on the ideXlab platform.

  • turbulent mixing in a richtmyer meshkov Fluid Layer after reshock velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.

  • Turbulent mixing in a Richtmyer–Meshkov Fluid Layer after reshock: velocity and density statistics
    Journal of Fluid Mechanics, 2012
    Co-Authors: B J Balakumar, Gregory C Orlicz, J R Ristorcelli, Sridhar Balasubramanian, Kathy Prestridge, Christopher Tomkins
    Abstract:

    The properties of turbulent mixing in a Richtmyer‐Meshkov (RM) unstable Fluid Layer are studied under the impact of a single shock followed by a reshock wave using simultaneous velocity‐density measurements to provide new insights into the physics of RM mixing. The experiments were conducted on a varicose SF6 Fluid Layer (heavy Fluid) interposed in air (light Fluid) inside a horizontal shock tube at an incident Mach number of 1.21 and a reflected reshock Mach number of 1.14. The light‐heavy‐light Fluid Layer is observed to develop a nonlinear growth pattern, with no transition to turbulence upon impact by a single shock (up to tU= D 23:4). However, upon reshock, enhanced mixing between the heavy and light Fluids along with a transition to a turbulent state characterized by the generation of significant turbulent velocity fluctuations ( u=U 0:3) is observed. The streamwise and spanwise root-mean-squared velocity fluctuation statistics show similar trends across the Fluid Layer after reshock, with no observable preference for the direction of the shock wave motion. The measured streamwise mass flux ( 0 u 0 ) shows opposing signs on either side of the density peak within the Fluid Layer, consistent with the turbulent material transport being driven along the direction of the density gradient. Measurements of three of the six independent components of the general Reynolds stress tensor (RijD u 00 u 00 ) show that the self-correlation terms R11 and R22 are similar in magnitude across much of the Fluid Layer, and much larger than the cross-correlation term R12. Most importantly, the Reynolds stresses (Rij) are dominated by the mean density, cross-velocity product term ( u 0u 0), with the mass flux product and triple correlation terms being negligibly smaller in comparison. A lack of homogeneous mixing (and, possibly, a long-term imprint of the initial conditions) is observed in the spanwise turbulent mass flux measurements, with important implications for the simulation and modelling of RM mixing flows.