Differences

This shows you the differences between two versions of the page.

--- advanced_settings [2012/08/11 09:36] – [Turbulence Model] marenlie
+++ advanced_settings [2018/07/29 21:29] (current) – removed enviadmin
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-====== Advanced Settings Panel ======
-{{ ::advanced_tab_small.jpg?nolink |}}
-Different to all other panels, the Advanced Settings Panel is used to change the way ENVI-met works.\\
-Therefore you must be very careful when changing settings on this panel.\\
-We recommend to take notes, what has been changed in order to trace back the effects in your simulation.
-Normally the user must not change settings in this section. \\
-All settings have been tested and found to be the best working configuration for most of the typical simulation tasks.\\
-Look at this panel as a kind of service menu like on your TV set. However, it is known that people are very attracted by this kind of service panels, especially if they include red buttons.
-The next sections will tell you the meaning of the different settings on the Advanced Settings Panel.
-===== General and Compatibility Settings =====
-=== Maximum Allowed Building Height (Default=100) ===
-Buildings above this height will be cut at the maximum height given here.\\
-The objective of this option is to keep Area Input File with the original building heights e.g. for skyscrapers and just cut them down in ENVI-met.
-=== Use small time steps for CO2 model (Default=No) ===
-Normally the CO2 system for the plant model can be handled like the other prognostic variables.\\
-It might be the case (e.g. if a huge amount of plants are in the area) that the CO2 model becomes unstable.
-In this case, turn this option into "Yes".\\
-In other cases, using small time steps will not change the model results, but increase the calculation time significantly.
-=== Use dynamic time steps (Default=Yes) ===
-The new option of dynamic time steps (see [[timesteps|[TIMESTEPS] Section]]) can be disabled here.\\
-For compatibility reasons only.
-=== Use longwave flux div in T-eqs (Default=Yes) ===
-Switches the longwave divergence term in the prognostic equation for air temperature off. For compatibility reasons only. \\
-(Simulations should not be made with different model versions!)\\
-For further information, look [[kb:lwflux|here]].
-===== Flow Model =====
-=== Maximum of SOR Iterations ===
-Number of SOR Iterations in the flow solver. \\
-Should be kept like this but may be adjusted to a smaller number if using the continuous wind field calculation (see [[timing|[TIMING] Section]]).
-=== Maximum of Update Steps ===
-Number of iterations to find a stable wind field.\\
-May be adjusted to a larger number if flow problems occur.\\
-(See also [[kb:flow|Knowledge Base: Flow Problems]]).
-===== Turbulence Model =====
-=== Use Buoyancy Term (Default=Yes) ===
-Allows to switch off the turbulence production through buoyancy forces.\\
-Might be helpful for certain low wind situations.\\
-**For a wind speed below 0.8 m/s, ENVI-met automatically turns //off// the buoyancy term.**
-=== Initial Relaxation (Default= 1.0) ===
-Sets the initial value of the [[relaxation]] coefficient.\\
-Reduce the value if problems with the TKE-e equation system occur constantly.\\
-See also [[kb:turbulence|Knowledge Base Turbulence Model]].
-=== Stationarity Criteria dK/dt (Default=0.010) ===
-Defines the threshold value of Km/dt below which further changes in the results are considered as numerical noise and the calculation is stopped to save time.
-=== Use Intelligent Troubleshooting ===
-Switches [[relaxation]] mechanism on or off.\\
-See also [[kb:turbulence|Knowledge Base Turbulence Model]].