Author: Michael Douglas White
Publisher:
ISBN:
Category :
Languages : en
Pages : 272
Book Description
High-resolution Numerical Simulation Scheme for Round Jets with and Without Swirl
Author: Michael Douglas White
Publisher:
ISBN:
Category :
Languages : en
Pages : 272
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 272
Book Description
Numerical Simulation of Turbulent Jets with Rectangular Cross-Section
Author: Robert V. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 24
Book Description
Three-dimensional turbulent jets with rectangular cross-section are simulated with a finite-difference numerical method. The full Navier-Stokes equations are solved at low Reynolds numbers, whereas at the high Reynolds numbers filtered forms of the equations are solved along with a subgrid scale model to approximate effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporal discretization and a fourth-order compact scheme is used for spatial discretization. Computations are performed for different inlet conditions which represent different types of jet forcing. The phenomenon of axis-switching is observed, and it is confirmed that this is based on self-induction of the vorticity field. Budgets of the mean streamwise velocity show that convection is balanced by gradients of the Reynolds stresses and the pressure.
Publisher:
ISBN:
Category :
Languages : en
Pages : 24
Book Description
Three-dimensional turbulent jets with rectangular cross-section are simulated with a finite-difference numerical method. The full Navier-Stokes equations are solved at low Reynolds numbers, whereas at the high Reynolds numbers filtered forms of the equations are solved along with a subgrid scale model to approximate effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporal discretization and a fourth-order compact scheme is used for spatial discretization. Computations are performed for different inlet conditions which represent different types of jet forcing. The phenomenon of axis-switching is observed, and it is confirmed that this is based on self-induction of the vorticity field. Budgets of the mean streamwise velocity show that convection is balanced by gradients of the Reynolds stresses and the pressure.
Numerical Simulation of the Turbulent Flow in Round Jets
Author: J. J. Lienau
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Numerical Simulation of Turbulent Jets with Rectangular Cross-section
Author: Robert V. Wilson
Publisher:
ISBN:
Category : Navier-Stokes equations
Languages : en
Pages : 26
Book Description
Publisher:
ISBN:
Category : Navier-Stokes equations
Languages : en
Pages : 26
Book Description
Large-Eddy Numerical Simulation of an Array of Three-Dimensional Impinging Jets
Author: M. H. Rizk
Publisher:
ISBN:
Category :
Languages : en
Pages : 189
Book Description
Numerical simulations of a row of impinging jets are performed. Both the impinging jets and the fountains caused by the collision of the wall jets are modeled in the simulations. The problem considered contains the essential features of twin jets impinging on the ground, simulating the hovering configuration of a VTOL aircraft. The flow is assumed to be governed by the time-dependent, incompressible Navier-Stokes equations. The large-eddy simulation approach is followed in which all scales resolvable by the grid resolution are computed explicitly, while the small-scale turbulence structures, which are nearly universal in character, are modeled by an eddy viscosity formulation that simulates the energy cascade into the small scales. The Navier-Stokes equations are solved using a staggered computational mesh. Central finite differencing is used to discretize all terms except the convective terms, which are discretized using the QUICK scheme. The Adams-Bashforth scheme is used to advance the solution in time. The pressure Poisson equation is used in place of the continuity equation. Efficient direct solutions are obtained for the pressure field, which allows the continuity equation to be satisfied at each time step. This study focuses on the motion and dynamics of large-scale structures that have been experimentally observed in jet flows. The behavior of the jets and the fountain due to introducing axisymmetric, azimuthal and random disturbances at the jet exists is investigated.
Publisher:
ISBN:
Category :
Languages : en
Pages : 189
Book Description
Numerical simulations of a row of impinging jets are performed. Both the impinging jets and the fountains caused by the collision of the wall jets are modeled in the simulations. The problem considered contains the essential features of twin jets impinging on the ground, simulating the hovering configuration of a VTOL aircraft. The flow is assumed to be governed by the time-dependent, incompressible Navier-Stokes equations. The large-eddy simulation approach is followed in which all scales resolvable by the grid resolution are computed explicitly, while the small-scale turbulence structures, which are nearly universal in character, are modeled by an eddy viscosity formulation that simulates the energy cascade into the small scales. The Navier-Stokes equations are solved using a staggered computational mesh. Central finite differencing is used to discretize all terms except the convective terms, which are discretized using the QUICK scheme. The Adams-Bashforth scheme is used to advance the solution in time. The pressure Poisson equation is used in place of the continuity equation. Efficient direct solutions are obtained for the pressure field, which allows the continuity equation to be satisfied at each time step. This study focuses on the motion and dynamics of large-scale structures that have been experimentally observed in jet flows. The behavior of the jets and the fountain due to introducing axisymmetric, azimuthal and random disturbances at the jet exists is investigated.
Numerical Simulation of a High Mach Number Jet
Author: M. Ehtesham Hayder
Publisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 816
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 816
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702
Book Description
Numerical Simulation of the Turbulence Structure of High-speed Jets
Author: K. Viswanathan
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Computations of Complex Three-Dimensional Turbulent Free Jets
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723544934
Category :
Languages : en
Pages : 218
Book Description
Three-dimensional, incompressible turbulent jets with rectangular and elliptical cross-sections are simulated with a finite-difference numerical method. The full Navier- Stokes equations are solved at low Reynolds numbers, whereas at high Reynolds numbers filtered forms of the equations are solved along with a sub-grid scale model to approximate the effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporary discretization and a fourth-order compact scheme is used for spatial discretization. Although such methods are widely used in the simulation of compressible flows, the lack of an evolution equation for pressure or density presents particular difficulty in incompressible flows. The pressure-velocity coupling must be established indirectly. It is achieved, in this study, through a Poisson equation which is solved by a compact scheme of the same order of accuracy. The numerical formulation is validated and the dispersion and dissipation errors are documented by the solution of a wide range of benchmark problems. Three-dimensional computations are performed for different inlet conditions which model the naturally developing and forced jets. The experimentally observed phenomenon of axis-switching is captured in the numerical simulation, and it is confirmed through flow visualization that this is based on self-induction of the vorticity field. Statistical quantities such as mean velocity, mean pressure, two-point velocity spatial correlations and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stress equations are presented to aid in the turbulence modeling of complex jets. Simulations of circular jets are used to quantify the effect of the non-uniform curvature of the non-circular jets. Wilson, Robert V. and Demuren, Ayodeji O. Langley Research Center NASA-CR-203976, NAS 1.26:203976, ICAM-97-101 NCC1-232...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723544934
Category :
Languages : en
Pages : 218
Book Description
Three-dimensional, incompressible turbulent jets with rectangular and elliptical cross-sections are simulated with a finite-difference numerical method. The full Navier- Stokes equations are solved at low Reynolds numbers, whereas at high Reynolds numbers filtered forms of the equations are solved along with a sub-grid scale model to approximate the effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporary discretization and a fourth-order compact scheme is used for spatial discretization. Although such methods are widely used in the simulation of compressible flows, the lack of an evolution equation for pressure or density presents particular difficulty in incompressible flows. The pressure-velocity coupling must be established indirectly. It is achieved, in this study, through a Poisson equation which is solved by a compact scheme of the same order of accuracy. The numerical formulation is validated and the dispersion and dissipation errors are documented by the solution of a wide range of benchmark problems. Three-dimensional computations are performed for different inlet conditions which model the naturally developing and forced jets. The experimentally observed phenomenon of axis-switching is captured in the numerical simulation, and it is confirmed through flow visualization that this is based on self-induction of the vorticity field. Statistical quantities such as mean velocity, mean pressure, two-point velocity spatial correlations and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stress equations are presented to aid in the turbulence modeling of complex jets. Simulations of circular jets are used to quantify the effect of the non-uniform curvature of the non-circular jets. Wilson, Robert V. and Demuren, Ayodeji O. Langley Research Center NASA-CR-203976, NAS 1.26:203976, ICAM-97-101 NCC1-232...