# Decalage angle

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Eugene, May 29, 2017.

1. Sep 5, 2019

### Eugene

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I was talking to someone with wind tunnel experience today. He was telling me that they start seeing separation after 5°. And for sure after 8° you will have separation at 100 MPH

Last edited: Sep 5, 2019
2. Sep 6, 2019

### Eugene

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Just wanna make sure that it looks right before I feel everything with Styrofoam

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3. Sep 6, 2019

### rtfm

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So what does styrofoam "feel" like

4. Sep 6, 2019

### plncraze

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I would like to thank rtfm for this test of self control and maturity.

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5. Sep 7, 2019

### proppastie

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Thought you were going to fabric cover.....quicker cheaper,....remember its a Polish aircraft. for test do not need to paint or finish just glue and shrink, at $4.35 a yard for un-certified bleed-cloth plus glue about$25 from where you are at.

6. Sep 7, 2019

### Eugene

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7. Sep 7, 2019

### Eugene

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Sorry, I will try to do better next time.

8. Sep 7, 2019

### Eugene

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Hope was to make somewhat flexible and flying experimental platform. Were I can add or remove foam between tuft testing. It's not at all about money. Money I have. What I don't have is time. That is why this project moving forward 10 times slower than I like.

9. Sep 7, 2019

### Eugene

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They didn't like my pictures from this morning and asked for dimensions. Maybe optical illusion. Pictures are not blueprints after all. That is OK. I can remove everything in 10 min and start all over again.

10. Sep 8, 2019

### Eugene

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OK, I was told to change the shape of my metal tube like you see on picture above. This way trailing edge will somewhat follow the shape of upper fuselage. Not sure how I will finish empty pocket under the tail boom at this point. But sure I can think about something when I get that far .

11. Sep 8, 2019

### TFF

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12. Sep 9, 2019

### Eugene

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Yes, to make it smaller was another recommendation. But only by about 15%. I was told that it need to be long enough so airflow from the bottom doesn't get pool up in to the prop. But to do 10 inches is too much, 6 will be good enough. And 48" under the prop will get smaller to 44-42".

13. Sep 9, 2019

### Eugene

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14. Sep 9, 2019

### Eugene

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15. Sep 9, 2019

### proppastie

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Who telling you. ...did they say the results too.....will you be happy with 5%....?

16. Sep 9, 2019

### Eugene

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I am talking to Russians with a lot of experience. Nobody else is talking to me anymore. American recommendation from EAA members is simple and with very predictable results - " sell it and get something better". This is right thing to do here in experimental aviation today. And yes nobody know what kind of result I will get. As long as I am willing to try, they telling my what they would try in my shoes. They not as spoiled as we are here. They still fixing things like we did long time ago.

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17. Sep 9, 2019

### Eugene

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18. Sep 9, 2019

### Eugene

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One of Skyboy owners send me this message. I think what he describe is tail volume for vertical tail is too small. I need someone smarter to confirm. Thank you.

19. Sep 9, 2019

### Speedboat100

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Try this:

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20. Sep 10, 2019

### plncraze

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Thank you for sharing what you are doing and what the folks in Russia think about this. There are a lot of smart folks there and since the average person here does not speak Russian we never hear their ideas. The separation they see after 5 or 8 degrees makes sense. High velocity air is low pressure and it wants to separate. Keep those drawings and pictures coming!

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