Recent content by Donny

Alright then, I guess we have to wait for it. Thanks for your help :)

Thank you for your reply. I don't really understand the concept. Could you please explain it to me a little bit more? Is it possible to calculate the pressure produced by the fans? the speed in m/s or ft/min?

Hello! Is there? I have a propeller fan and I want to know what is the pressure, CFM, speed, etc. based on it's blade length, the number of blades, etc. I already have a wind turbine generator and I seem can't find one for fans (propeller fan). Or is there a way to find those parameters? Any...

oke thank you for your explanation. And also whoever replied to this thread. I'll figure it now. ;)

When working on a prototype or a small model can I assume in all condition the Reynold's number are the same? For example, same speed, same temperature, etc will result the same Re.

Any idea of how to do that? I wonder wether that will be possible or not. I'm not really understand that.

Can it be possible to regulate the fans not using rheostat? I hope I can use a computer for example.

Hello! Is it possible to control the suction volume, so the volume can be increased and decreased on demand using computer? Thanks.

Interesting facts, I never know about that before. You said that drag calculation was affected by Reynold's number, but how to get the right Reynold's number value when we are talking about wind tunnel and there is an object in it. Is it true that different size of an object, temperature and...

Can I neglect it when talking about drag force or making a wind tunnel test? Why is it so important? Thank you for replying.

I want to calculate what is the safest ratio for blockage ratio. Here is the diagram. As you can see, the ball is in the middle of the tube. The ball has blockage ratio which is Area of ball:Area of tube I want to compare my blockage ratio with the standard blockage ratio for wind tunnel.

Anyone? Could somebody please point me how to get it? ebook, website, etc?

Hello! Anyone can help me to find the best blockage ratio between for a small ball in tube? so the pressure can stay up (not drop). How to calculate it. Thank You.

Hello Sir! Thank you for your reply. I have changed the design, right now I want to calculate drag force on this model (attached). There are two questions there. The first one could you give me a hint of how to solve the force of the slope area, and the second one is the drag force of the...

Hello friends, I have a problem in Bernoulli equation and Newton Law. I'm going to calculate how much power is needed to lift up an object with weight W. I'm planning to put the object in a 10 inches diameter. How can I calculate the power needed by the motor to lift up the object? Does...