Hi, I will like to design this vertical wind tunnel (large nozzle) to shoot air out at 10 m/sec at the exit and a diameter of 8 ft.
However I want to understand the following parameters. Does anyone know about this? and know how to calculate the following parameters ?:
We want V2=10m/sec (outlet velocity at jet)
I want to design a fan or number of fans arranged (or framed together) that can do the job and how can these fans be selected?
1. Does the contraction ratio (Alarge/Asmall or Ainlet/Aoutlet) should be kept at 8 only from a square to circular contraction? or can any contraction ratio should be used?
2. Does the continuity equation applies? Can you find the total required flow rate Q1 if you have V2=10 m/sec? Can you use: Q1=Q2 thus Q1=A2*V2?
3. How do you find the total loss?
4. How do you find the dynamic head (both at inlet and outlet)?
5. How do you find the static head (both at inlet and outlet)?
6. How do you find the total pressure head?
7. How do you find the total power required (horsepower)?
8. How do you find the "Backpressure of the system?
9. How do you find the pressure being pushed through the exit cone?
10. How do you find the total pressure in inches of water?
11. How do you select a fan? what parameters do you need?
12. How do you select a complete multiple fan assembly?
13. Can I place several fans in a rectangular matric at the inlet or can they be placed circular? what is the best way?
14. What is the best material to build this of? (aluminum, steel or plywood?) what thickness is ideal?
15. What is a good physical closing-opening mechanism at the outlet?
16. How can a frame be designed to hold something like this?
17. Can all these parameters be obtained from an Ansys v19 simulation?
18. How can this be developed simple in Ansys 19 fluent if I have the CAD file?
19. How can I develop in Mathcad file? or should it be done in Matlab script instead?
20. How can I obtain Inches of water in Mathcad?
Wind tunnel design is as much "black art" as science. A short pass at a few of the simpler answers:
There are a number of books. Low Speed Wind Tunnel Testing, Pope and Rae, might be a good place to start. There are newer editions, an older one might have more "rules of thumb."
Topic about "Ansys and Mathcad" integration: https://community.ptc.com/t5/PTC-Mathcad-Questions/Ansys-and-Mathcad/td-p/133878
Video "ANSYS Fluent for Beginners: Lesson 1(Basic Flow Simulation)": https://www.youtube.com/watch?v=fxFZyiWt_Xc