Looking for help running a simulation
Posted: Wed Jun 22, 2016 9:48 pm
Intro:
I'm a student in a french scientific prep school. I've taken upon myself as a TIPE project ( personal investment project) to study and helicopter's flapping hinges on rigid blades and how they help solve the dissymmetry of lift phenomenon.
I've come to the latest stage of my study. Did the meshing with Salome, and wanted to run the simulation but failed to do so as code-saturne sends me a "Process not running" message.
Mesh:
I do apologize for the complete mess that geometry is, but this is what i tried to do:
1st Blade Tip creation:
- Import my points to define the airfoil profile.
- Translate said points and create a face at given position.
- Draw lines between each point of intrados and extrados to make centers of mass for each line.
- Using these centers of mass create vectors normal to the face then rotate them by 90 degrees to make them normal to the line.
- use said normal vectors to create a third point by rotating points of the extrados by 90 degrees.
- Draw circles with set tri-points and make faces out of these.
- There are a few i added manually to define the spherical shape at the top.
- Extrusion across path which is a polyline going through all centers of mass
Making the fluid's domain:
- Cut the geometry using a box to leave only half.
- Extrude generated planar face to have the main blade.
- Create a box which will be the fluid's domain.
- Cut both Wing Tip and main Wing out of the box.
At this stage i first thought i was ready for the simulation. But I realized that what i wanted is a rotating blade not a still one so i decided to make the wind's speed vary instead of the blade's. Then again i did not know how to make fluid speed a function of space in code saturne. Thus i decided to add a part on which i'll have multiple inlets(faces) each with a speed higher than the one before.
Making the extra part:
-Create a simple box.
-create a smaller box with desired length of discretization.
- Use multi translation and cut function to have the crank shape which guarantees our multiple inlets.
Making the mesh:
- After creating a partition of the two solids and exploding it did the mesh for each of them and then compounded the meshes.
- Then created the groups with walls inlets and outlets.
Code-Saturne part:
- Thermophysical Models : Unsteady flow, k-epsilon turbulence model, the rest at default.
- Physical properties at default except i chose for there to be gravity.
- Volume conditions at defaults.
- Definition of boundary conditions set as in the names in the mesh.
- Boundary conditions : Inlets fluid speed norm set as [ u_norm = 55.6+value*sin(47.1*t) ] , 55.6 being the helicopter's forward speed, and value*sin(47.1*t) being the blade's rotation speed, with "value" varying given the inlet.
- Then i set results to be MED format.
That's about it. Thanks for giving this some of your time. I'd very much appreciate any kind of help in this endeavor.
Cordially,
Salim ELHAMDANI
I'm a student in a french scientific prep school. I've taken upon myself as a TIPE project ( personal investment project) to study and helicopter's flapping hinges on rigid blades and how they help solve the dissymmetry of lift phenomenon.
I've come to the latest stage of my study. Did the meshing with Salome, and wanted to run the simulation but failed to do so as code-saturne sends me a "Process not running" message.
Mesh:
I do apologize for the complete mess that geometry is, but this is what i tried to do:
1st Blade Tip creation:
- Import my points to define the airfoil profile.
- Translate said points and create a face at given position.
- Draw lines between each point of intrados and extrados to make centers of mass for each line.
- Using these centers of mass create vectors normal to the face then rotate them by 90 degrees to make them normal to the line.
- use said normal vectors to create a third point by rotating points of the extrados by 90 degrees.
- Draw circles with set tri-points and make faces out of these.
- There are a few i added manually to define the spherical shape at the top.
- Extrusion across path which is a polyline going through all centers of mass
Making the fluid's domain:
- Cut the geometry using a box to leave only half.
- Extrude generated planar face to have the main blade.
- Create a box which will be the fluid's domain.
- Cut both Wing Tip and main Wing out of the box.
At this stage i first thought i was ready for the simulation. But I realized that what i wanted is a rotating blade not a still one so i decided to make the wind's speed vary instead of the blade's. Then again i did not know how to make fluid speed a function of space in code saturne. Thus i decided to add a part on which i'll have multiple inlets(faces) each with a speed higher than the one before.
Making the extra part:
-Create a simple box.
-create a smaller box with desired length of discretization.
- Use multi translation and cut function to have the crank shape which guarantees our multiple inlets.
Making the mesh:
- After creating a partition of the two solids and exploding it did the mesh for each of them and then compounded the meshes.
- Then created the groups with walls inlets and outlets.
Code-Saturne part:
- Thermophysical Models : Unsteady flow, k-epsilon turbulence model, the rest at default.
- Physical properties at default except i chose for there to be gravity.
- Volume conditions at defaults.
- Definition of boundary conditions set as in the names in the mesh.
- Boundary conditions : Inlets fluid speed norm set as [ u_norm = 55.6+value*sin(47.1*t) ] , 55.6 being the helicopter's forward speed, and value*sin(47.1*t) being the blade's rotation speed, with "value" varying given the inlet.
- Then i set results to be MED format.
That's about it. Thanks for giving this some of your time. I'd very much appreciate any kind of help in this endeavor.
Cordially,
Salim ELHAMDANI