JHU Turbulence Database: Analysis Tools Documentation

The JHU Turbulence Database Cluster turbulence.pha.jhu.edu
Dataset descriptions Instructions to access via Web services interface (using Fortran, C or Matlab running on client computer) Access via web-browser Analysis tools documentation (interpolation algorithms, differentiation, etc..) Publications People and credits Citing the database in your work Related group webpages Links to other turbulence and fluid dynamics datasets Home		Database Functions GetVelocity GetVelocityAndPressure GetForce GetVelocityGradient GetPressureGradient GetPressureHessian GetVelocityLaplacian GetVelocityHessian FOR DETAILED FORMULAE USED IN THE FUNCTIONS, DOWNLOAD DOCUMENT Database Spatial Differentiation Options: *Options for GetVelocityGradient and GetPressureGradient* FD4: 4th-order centered finite differencing (can be spatially interpolated) FD6: 6th-order centered finite differencing (without spatial interpolation) FD8: 8th-order centered finite differencing (without spatial interpolation) *Options for GetPressureHessian, GetVelocityLaplacian and GetVelocityHessian* FD4: 4th-order centered finite differencing (can be spatially interpolated) FD6: 6th-order centered finite differencing (without spatial interpolation) FD8: 8th-order centered finite differencing (without spatial interpolation) Database Spatial Interpolation Options: *Interpolation options for GetVelocity, GetVelocityAndPressure, and GetForce* NoSInt: No Space interpolation (value at the datapoint closest to each coordinate value) Lag4: 4th-order Lagrange Polynomial interpolation along each spatial direction\| Lag6: 6th-order Lagrange Polynomial interpolation along each spatial direction Lag8: 8th-order Lagrange Polynomial interpolation along each spatial direction *Interpolation options for GetVelocityGradient, GetPressureGradient, GetPressureHessian, GetVelocityLaplacian and GetVelocityHessian* FD4NoInt: No interpolation (value of the 4th order finite-difference evaluations at the datapoint closest to each coordinate value is returned) FD6NoInt: No interpolation (value of the 6th order finite-difference evaluations at the datapoint closest to each coordinate value is returned) FD8NoInt: No interpolation (value of the 8th order finite-difference evaluations at the datapoint closest to each coordinate value is returned) FD4Lag4: 4th-order Lagrange Polynomial interpolation in each direction, of the 4th-order finite difference values on the grid. Database Time Interpolation Options: *For all variables and derivatives listed above, the two options are:* NoTInt: No interpolation (the value at the closest stored time will be returned). PCHIP: Piecewise Cubic Hermite Interpolation Polynomial method is used, in which the value from the two nearest time points is interpolated at time t using Cubic Hermite Interpolation Polynomial, with centered finite difference evaluation of the end-point time derivatives (i.e. a total of four temporal points are used).

The JHU Turbulence Database Cluster

turbulence.pha.jhu.edu

Dataset descriptions

Instructions to access via Web services interface (using Fortran, C or Matlab running on client computer)

Access via web-browser

Analysis tools documentation (interpolation algorithms, differentiation, etc..)

Publications

People and credits

Citing the database in your work

Related group webpages

Links to other turbulence and fluid dynamics datasets

Home

Database Functions

GetVelocity
GetVelocityAndPressure
GetForce
GetVelocityGradient
GetPressureGradient
GetPressureHessian
GetVelocityLaplacian
GetVelocityHessian

FOR DETAILED FORMULAE USED IN THE FUNCTIONS, DOWNLOAD DOCUMENT

Database Spatial Differentiation Options:

Options for GetVelocityGradient and GetPressureGradient

FD4: 4th-order centered finite differencing (can be spatially interpolated)
FD6: 6th-order centered finite differencing (without spatial interpolation)
FD8: 8th-order centered finite differencing (without spatial interpolation)

Options for GetPressureHessian, GetVelocityLaplacian and GetVelocityHessian

FD4: 4th-order centered finite differencing (can be spatially interpolated)
FD6: 6th-order centered finite differencing (without spatial interpolation)
FD8: 8th-order centered finite differencing (without spatial interpolation)

Database Spatial Interpolation Options:

Interpolation options for GetVelocity, GetVelocityAndPressure, and GetForce

NoSInt: No Space interpolation (value at the datapoint closest to each coordinate value)
Lag4: 4th-order Lagrange Polynomial interpolation along each spatial direction|
Lag6: 6th-order Lagrange Polynomial interpolation along each spatial direction
Lag8: 8th-order Lagrange Polynomial interpolation along each spatial direction

Interpolation options for GetVelocityGradient, GetPressureGradient, GetPressureHessian, GetVelocityLaplacian and GetVelocityHessian

FD4NoInt: No interpolation (value of the 4th order finite-difference evaluations at the datapoint closest to each coordinate value is returned)
FD6NoInt: No interpolation (value of the 6th order finite-difference evaluations at the datapoint closest to each coordinate value is returned)
FD8NoInt: No interpolation (value of the 8th order finite-difference evaluations at the datapoint closest to each coordinate value is returned)

FD4Lag4: 4th-order Lagrange Polynomial interpolation in each direction, of the 4th-order finite difference values on the grid.

Database Time Interpolation Options:

For all variables and derivatives listed above, the two options are:

NoTInt: No interpolation (the value at the closest stored time will be returned).

PCHIP: Piecewise Cubic Hermite Interpolation Polynomial method is used, in which the value from the two nearest time points is interpolated at time t using Cubic Hermite Interpolation Polynomial, with centered finite difference evaluation of the end-point time derivatives (i.e. a total of four temporal points are used).