We are trying to simulate our dimpled-VAWT design thru a virtual wind tunnel. Our design is combination of Darrieus and Savonius blade rotor. Our goal is to compare its efficiency to a no-dimple VAWT. We already did few simulations but kind of doubting ourselves with the results.
Just have quite few questions:
Are supposed to simulate the design as a single body or much better if separate body (Darrieus and Savonius)?
With regards on computing the drag and lift coefficients, we set the lift on X axis (perpendicular to the wind) and drag on Y-axis (parallel to the wind). Is it the correct flow considering our design and virtual wind tunnel?
We also wanted to get the power output (if possible), is there a way to simulate it on the Simscale or do we have to manually compute it using other parameters?
We are still students and kind of still struggling with the use of SIMSCALE as we mostly relies on tutorials from YT and Simscale forum/blogs. Feel free to provide feedback or tips that we can use to better improve our research such as other parameters to focus with and such.
It depends on what you want to do really. From a simulation perspective, for a flow simulation like you are trying to run in your project at the moment, regardless of your assembly or the original model, the simulation only considers the flow region volume and not the original bodies itself that you have already deleted. If you were to run a structural simulation, going forward, as part of a one-way FSI for example, you can then have multiple studies as to which one suits your design requirements better for single or separate body designs. You can do the same for flow simulations if it affects the flow region volume and you believe there would be variation in overall lift generation, etc.
This depends on which face you have selected for lift generation calculation. Have you taken a look at this article already: How To Analyze the Pitch, Lift, and Drag Coefficients | SimScale
I can see you have selected the entire VAWT for this at the moment. This makes it a bit tricky, but I guess the right question to ask here is whether you really want to calculate the moment for the entire setup or just one of the lift generating blades? When you select 1 blade for the result control for example, depending on the orientation of the blade, you can then choose the directions of drag and lift for that particular blade very clearly and easily as follows (relative to local wind direction and airfoil orientation):
For the selection of the entire setup, it becomes your decision to make as to which direction you select and want to study. But in my opinion, the lift direction would keep changing for each blade instantaneously and it is a bit tricky to determine a single lift direction for the entire VAWT, unlike an airplane wing where the lift would always be perpendicular to the (only) wing angle.
Thank you for your insights. After conducting some research, we decided to follow the tutorial Drone Simulation Using Rotating Zones as a reference, as we wanted to analyze the flow simulation when the turbines are rotating.
We decided to test the H-rotor first for faster computability as well, and later on we will try to do the save to the Savonius rotor. Based on simulations, we have gotten couple of torques on various windspeed which is something we wanted to get as well to get the power output later on.
However, we are still in the somehow in the dark on the lift coefficients. Here are my questions:
Is our force plot kind of reasonable values especially the Torque at various wind speeds?
I am thinking of creating multiple force and moment coefficients for each blade as to test whether they will have different values in terms of lift. Is my idea somehow will work?
Thank you in advance. Any feedback or suggestions will be very helpful.
Btw, this is a base design (without dimple) since we will be comparing it to the dimpled designs if in case we are on the right track. TIA.
