Bikkani, Ravi Kiran (2005-08). Charecterization of inertial and pressure effects in homogeneous turbulence. Master's Thesis. Thesis uri icon

abstract

  • The objective of the thesis is to characterize the linear and nonlinear aspects of inertial
    and pressure effects in turbulent flows. In the first part of the study, computations of
    Navier-Stokes and 3D Burgers equations are performed in the rapid distortion (RD) limit
    to analyze the inviscid linear processes in homogeneous turbulence. By contrasting the
    results of Navier- Stokes RD equations and Burgers RD equations, the effect of pressure
    can be isolated. The evolution of turbulent kinetic energy and anisotropy components
    and invariants are examined. In the second part of the thesis, the velocity gradient
    dynamics in turbulent flows are studied with the help of inviscid 3D Burgers equations
    and restricted Euler equations. The analytical asymptotic solutions of velocity gradient
    tensor are obtained for both Burgers and restricted Euler equations. Numerical
    computations are also performed to identify the stable solutions. The results are
    compared and contrasted to identify the effect of pressure on nonlinear velocity gradient
    dynamics. Of particular interest are the sign of the intermediate principle strain-rate and
    tendency of vorticity to align with the intermediate principle strain-rate. These aspects of
    velocity gradients provide valuable insight into the role of pressure in the energy cascade
    process.

publication date

  • August 2005