Airfoil Reynolds Number

[doug.hunsaker]

Question from user: 

hi, i was trying your program online just to test a wing in water how can i change the properties of the fluid in machup online thank you

[doug.hunsaker]

MachUp is all non-dimensional. So, as long as your airfoil properties on the wing are taken at the correct Reynolds number, it can apply to virtually any fluid.

[doug.hunsaker]

Response from user:

Sure, but how can i change the Reynolds number cause Cd are sensitive

to variations in Reynolds and Cl and Cm are sensitive too for high

values of alpha.

[doug.hunsaker]

On MachUp Web, you have access to the airfoil properties when you click on the Root Airfoil or Tip Airfoil dropdown menus. These appear on the right-hand side when you have a wing selected. You can change the lift slope, drag coefficients, moment slope, etc. all right there.

Those coefficients depend on Reynolds number, so you'll need to obtain those coefficients somehow from and airfoil prediction tool, such as Xfoil. We'll be releasing CloudFoil soon, which is another tool designed for predicting airfoil aerodynamic properties at varying Reynolds numbers.