# Search results

1. ### Wind turbine blade geometry

Hi guys: I work on DIY wind turbine and I plan to make a twisted blade .... I need to know what does it mean that blade AOA is 6 degrees... I mean if the blade is twisted that 6 degrees angle refers to where root ,tip,or root???? Thank you in advance
2. ### Wind turbine stability

Hi guys . You may ask this is not the site for such thing. However i think for aerodynamics it is one of the best sites to get what you are looking for.
3. ### problems of a two blade rotor

hi guys:I have been out for long time...I am usually in auto conversion forum..but for the time being I am working on a 2-blade wind tubine.and I need your advice on problems relegated to that including normal operation and also during yawing(when the wind change direction.thanks
4. ### HOVER AND FORWARD SPEED RPM.

HI GUYS: in most of the articles i read about power required for the helicopter during forward flight with speed from above 25 knots up to 70 knots at least is that, the power required is less than that for hover .and as i understand for that to happen the collective is lowered during forward...

Hi guys: What is the rule of thumb (if any)for main rotor solidity with given disk loading? Assming i have a 2000 lb helicopter with disk loading of say 4 lb/ft2 (rotor disk area about 500 ft2),how much blades should the rotor have ? Is there any formula or equation for such calculation...
6. ### position of tail to main rotor.

Hi guys Is there any guidance on positioning the tail rotor of helicopter to main rotor ? Thank you in advance.
7. ### induced velocity

Hi guys : I understand the induced velocity equation parameters. it says that it the velocity of the air downwards as result of air disturbance created by rotating blades. what I don't understand how come this effect goes like this : The smaller the rotor d the higher the IV the higher the...
8. ### tandem helicopter

Hi guys : In artical about those helicopters it is said the helicopter front side should be tilted down a little bite before go from hover to forward flight.? What could be the reason for that? The only thing I can think of is reducing the drag? Is that right? And if no,what are the other...
9. ### tail horiz and vert stabalizers

Hi guys : What would be my tail horizontal and vertical stabilizer areas compared to wing area? My wing area is about 100 ft2. I found in the net that the tail horizontal stab is about 25-30% of the wing area. And the vertical stab is only 60% of the horizont I know it depends on the...
10. ### driving pulley of PSRU

Hi guys : I have seen a lot of images on psru on the net, and I got the idea. What I need to know is if the clutch is the part of engine that receives rotation when engaged with flywheel and then delivers it through speed shaft to speed gearbox, Does that mean I need to include the clutch...
11. ### optimal propeller rpm

Hi guys :@ 7000ft this engine will give about 75% (61.7hp)
12. ### location of CG and AC for pusher design

Hi guys I have been out for some time. I plan for pusher design and I got difficulty identify my AC and CG because the engine in the back along with tail parts are much heavier than me and I end up with what you call negative stability . Any advice. Please.
13. ### tandem helicopters

hi guys: is it a must for tandem helicopters that overall disk loading is less than disk loading of rotor 1+ disk loading of rotor 2? what is the reason for that ?i mean what if rorors are put far enough from each other.? this way the rear rotor would be less affected by front rotor.and...

Hi guys: I have read some articles about wing loading and power loading and I got the idea that wing+power loading should make less than 25 for flyable airplanes .but I found also that some airplane that number is more than 30 . what does that mean? . If I reduce HP I have to go with high...
15. ### propeller dimensions.

Hi guys Iam working on homemade wooden propeller and I nerd to know if the prop width ( average) is about 10-15 % of prop D and the max thickness of is about 10-15 % of the width? meaning if I have 60" (5ft) prop, the width should be about 15-20 cm and the max airfoil thickness should be...
16. ### tandem wing design

Hi guys What is the most usual tandem wing design , with front and rear wing scenery? what are the aerodynamic points to consider, tail or tailess, airplane CG ,how the airplane is controlled without tail stabilizer and rudder? Some images would be helpful? thank you.
17. ### prop tip speed for best effeciency.

Hi guys I have been looking for info on best prop speed for best efficiency. And I got different answers, some say that for crushing the prop tip speed should be less than 700 f/sec, other sites recommends the best tip speed is at speed close to. 82 -.92 speed of sound but not more. Assuming...
18. ### airplane balance

Hi guys I need to know how does the tail stabilizer makes thrust downwards. the only thing I think of is putting it as a wing but upside down.your help of great appreciation.
19. ### tandem wing pusher

Hi guys I want such design for short wingspan,yet I do not know if such design is OK. I need both wings to make same amount of lift , and no idea where the controlling flaps and ailerons to be fitted( front or rear wing), and where should be the CG, do I need rudder and stabilizer for such...
20. ### auto conversion with pusher design.

Can I go with pusher design for my auto conversion . I need to enjoy the veiw ,have short fuselage ,get rid of gyroscopic load .and most important the the prop thrust load will tend to push towards the psru assembly which ,I think is more reliable than in case of pulling outwards . Of course I...