i am now a student at swansea university, we have a project up coming to design, build and impliment a 2m^2 sweep area wind turbine to be mounted atop one of our buildings (we officially live in the windiest place in england) what kind of differences will i need to set up for this to compute accuratly (for example factoering in the rotation of the blade into the airflow calculations and similar
Hi @Lemlurker, I started an optimisation project on a wind turbine and I’m working on the next iteration…
There are a few good references I used at the bottom, my next write up will include more info on cord length distribution. One of the references gives a lot to think about including potential power, typical efficiencies, blade design etc: http://www.gurit.com/files/documents/2aerodynamicspdf.pdf
I also have a matlab file if your interested to calculate blade twist with input variables like design wind speed, rpm blade size… should be easy to adapt to your needs!
If you have more specific questions I’ll do my best to answer!
thanks for the help, i guess the main thing im interested in is how i could read out the amount of torque i would get out of my turbine, and i guess aditionally how can you factor in the change in blade aoa due to its rotation. also im very interested in how you go through the process of optimiseation, how do you know what to change and what to modify, how do you go from a very basic turbine blade and work through modifying it up to an efficient blad (btw ive got 1 month to design this!)
1 month is not a lot of time I think Ive just taken a 1 month break from this project
One you have a design you can simulate it read the tongue from the forces and moment results control option in SimScale.
As for optimising, calculations go a long way however don’t leave it too long before simulating and validating your design, I came in confident of a solid design and actually my first design didn’t meet my expectations at all.
I think for the size of your wind turbine will mean there won’t be much twist, I would if I was on a time limit pick one aerofoil profile, calculate the angle at say 10 points add a few degrees for lift generation (say 5) put it into the cad software of your choice (I use OnShape and I have an aerofoil script there you can use) and then just generate your blade. Move to SimScale and then you will early on see what your doing write and what your doing wrong (you can use my setup for a template). One side point is I didn’t look much into the cord length distribution, if your using a single profile I think the rule is Cord=maxwidth/radius (double check that), giving you a thick base and thin tips.
You might realise after the simulation that certain things art correct or are slightly miscalculated, calculations are good but the can’t account for everything, SimScale however does a good job at that!
so a summary:
- Tip Speed Ratio (look this up, think you need to aim for about 6-10?)
- Blade Twist Calculations
- Blade Cord length Distribution Calculations
- CAD model
- CFD Analysis
- Recalculations using observations
- Modify CAD model
- Structural Design (Its only a good design if it can be actually made)
- Build and test
I think calculations should take no longer than a day there is too much work to do after!! I use Matlab just to produce the mass amount of numbers but I’m sure if this is unfamiliar as it was in my first year excel will be fine.
Good luck, don’t hesitate if you have more questions or want to use any of my tools.
Torque and speed from rotating turbine?