hi rb1957...
its been so long but still can not find "why"...
1. yes i got negative result
2. i'm not an aerodynamicist so i don't know about your 2nd question. what i can tell you is the force balance is used in a wind tunnel.
is it possible the problem is come from the center of gravity of...
Hi btrueblood,
thank you very much for your explanation. actually i'm not an expert in aerodynamics area. all the software was developed by a programmer in my office. he said he sure that all his aerodynamics formula in the software is correct. this problem is really confusing for me.
by the...
Hi rb1957,
Yes of course when calibrating i apply a known load. the drag was calibrated in negative direction and of course the apply load was in negative too. is it a problem if i apply the load in negative? but the checkload give me a good result. it seems like an aerodynamic problem...
Hi btrueblood,
some peoples said that the problem is come from the software. I have 3 software, calibration software, check load, and data acquisition. The forces are in kg and the moments are in kgm, when calibrating the moments i enter the force too e.g when i calibrate the pitching moment i...
This is my first thread, i want to say thanks to this great forum.
I have a problem with negative drag on an airfoil model. I have a strain gauge balance which can measure 3 forces and 3 moments. I attach an airfoil model to the balance and did some angle sweeping on a wind tunnel to capture...