# Wolf Dynamics - Multiphysics simulations, optimization, and data analytics

## Calculator for the estimation of turbulence properties values (boundary and initial conditions)

How to use the calculator:

Select what you want to compute in the turbulence variables section. In the properties section set the compulsory values according to what you want to compute. Finally, press the compute button.

Additionally, according to the turbulence intensity, you can use the preset values of turbulence intensity and eddy viscosity ratio.

If you are missing a value, you will get a popup window with the related error.

 Cells with missing values are colored red. Cells with the output values are colored green. Cells with the correct values are colored blue.

 Properties - Input values Freestream velocity $$U_{\infty}$$ $$m/s$$ Turbulence kinetic energy $$\kappa$$ $$m^2/s^2$$ Turbulence dissipation $$\epsilon$$ $$m^2/s^3$$ Specific turbulence dissipation $$\omega$$ $$1/s$$ Turbulence intensity $$Tu$$ $$\%$$ Turbulence length scale $$Tu_L$$ $$m$$ Kinematic viscosity $$\nu$$ $$m^2/s$$ * Eddy viscosity ratio $$\mu_t / \mu$$ [] * Kinematic viscosity at room temperature: Air: $$1.5^{-5}$$ - Water: $$1.0^{-6}$$ Choose turbulence variables to compute Compute $$\omega$$ from $$\kappa$$ and $$\epsilon$$ $$( \beta^* = C_{\mu} = 0.09)$$ Compute $$\epsilon$$ from $$\kappa$$ and $$\omega$$ $$( \beta = C_{\mu} = 0.09)$$ Compute turbulence variables $$( \kappa$$, $$\epsilon$$, $$\omega )$$ from $$Tu$$, $$Tu_L$$ and $$U_{\infty}$$ Compute turbulence variables $$( \kappa$$, $$\epsilon$$, $$\omega )$$ from $$Tu$$, $$\mu_t / \mu$$, $$U_{\infty}$$ and kinematic viscosity $$\nu$$ Compute turbulence intensity $$(Tu )$$ from $$\kappa$$ and freestream velocity $$( U_{\infty} )$$ Compute turbulence length scale $$(Tu_L)$$ from $$\kappa$$ and $$\epsilon$$ Compute turbulence length scale $$(Tu_L)$$ from $$\kappa$$ and $$\omega$$ Compute turbulence eddy viscosity ratio $$(\mu_t / \mu )$$ from $$\kappa$$ and $$\epsilon$$ Compute turbulence eddy viscosity ratio $$(\mu_t / \mu)$$ from $$\kappa$$ and $$\omega$$ Warning. The formulas used to estimate the turbulence quantities values may vary from software to software. For more information, visit the following links:         NASA Turbulence Modeling Resource       https://turbmodels.larc.nasa.gov/          CFD-Online Turbulence free-stream boundary conditions       https://www.cfd-online.com/Wiki/Turbulence_free-stream_boundary_conditions Choose preset values of turbulence intensity and eddy viscosity ratio Choose turbulence intensity level:    Low turbulence case Medium turbulence case High turbulence case Low turbulence case: external flow around cars, ships, submarines, and aircrafts. Medium turbulence case: flow in not-so-complex devices like large pipes, fans, ventilation flows, wind tunnels, or low speed flows. High turbulence case: high-speed flow inside complex geometries like heat-exchangers and rotating machinery (turbines and compressors).