Wind field simulations at Askervein hill - WindSim

1. INTRODUCTION............................................................................................................. 4
1.1. THE HOST COMPANY ......................................................................................................... 4
1.2. THE WINDSIM PROJECT .................................................................................................... 4
1.2.1. Electricity in Norway ................................................................................................ 4
1.2.2. Wind resources in Norway ........................................................................................ 5
1.2.3. Description of the project.......................................................................................... 5
1.3. SUBJECT OF THE PRESENT STUDY...................................................................................... 6
1.4. THE ASKERVEIN HILL CASE : BACKGROUND INFORMATION.............................................. 6
2. DESCRIPTION OF THE STUDY................................................................................... 8
2.1. PRELIMINARY ASSUMPTIONS............................................................................................. 8
2.2. TURBULENCE MODEL........................................................................................................ 8
2.2.1. Mixing length model.................................................................................................. 8
2.2.2. k-ε model ................................................................................................................... 9
2.2.3. Two scale k-ε model ................................................................................................ 10
2.3. NUMERICAL SETUP.......................................................................................................... 11
2.3.1. Calculation domain................................................................................................. 11
2.3.2. Boundary conditions ............................................................................................... 11
3. SIMULATIONS AND RESULTS .................................................................................... 15
3.1. GRID TESTING ................................................................................................................. 15
3.1.1. Number of cells........................................................................................................ 15
3.1.2. Grid grading............................................................................................................ 21
3.2. INLET PROFILES............................................................................................................... 26
3.3. BOUNDARY CONDITIONS................................................................................................. 26
3.4. TURBULENCE MODEL...................................................................................................... 29
4. CONCLUDING REMARKS ............................................................................................ 34
5. REFERENCES................................................................................................................... 36
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