aarhus universitet flexsim janus larsen 2011 1 the task the solution hdlite flexsim horsens fjord...
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AARHUSUNIVERSITET
FlexSimJanus Larsen
20111
•The task
•The solution
•HDLite
•FlexSim
•Horsens fjord
FlexSim - a simple but flexible tool for ecological fjord modeling.
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
The task›Make a modeling tool to: › estimate fjord modification of loads from the Danish
watersheds in different scenarios› assess the ecological state in Danish fjords in different
scenarios
›The tool must be:› easy to implement on new fjords› have computational times in the order of minutes for
yearly simulations
›Wish list:› Decouple physics and biology› Separate biological and programming expertise
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
The solution›FlexSIM› Model setup including the ecological equation system is inputted to a
precompiled model engine.› Highly flexible enabling both very fast ‘box’ setups and high resolution 3D
computational grids.
›HDLite: Combined box model-3D model concept
› Water volumes are exchanged between cells as in a box model› Fluxes between boxes are automatically calculated from the computational
grid geometry and simple physical assumptions:› Stratification is created by freshwater runoff in the surface and penetration of
denser salt water from the open boundaries by horizontal mixing.› Stratification is eroded by wind induced vertical mixing.› The timestep is limited only by the size of the cells and the mixing
coefficients
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
Horsens fjordBathymetry
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
Horsens fjordSalinity
Course box model 1 year HDLite only in ~10 sec.
Timestep = 3600 sec.
Mixed mesh model1 year HDLite only in <10 min.
Timestep = 120 sec.
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
Modeling without programming…1. Copy the model engine executable to your windoze computer2. Use a text editor to create or modify mesh, bathymetry and setup files3. Run the engine from the command prompt with your setup file as input
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011
AARHUSUNIVERSITET
FlexSimJanus Larsen
2011