Concerning the Airfoil of Variable Pitch propellers

In summary, a variable pitch propeller uses a mechanism to tilt the blade to change the pitch. This allows the propeller to produce more thrust at higher speeds.
  • #1
Jarfi
384
12
Hello, I am not an expert in aerospace engineering, merely a hobbyist so bear with my ignorance.

lately I have been thinking of creating my own propeller and variable pitch system using a CNC machine as a longer term goal. This desire arose due to the fact that there are no commercially available variable pitch systems for RC-aircraft on the electric scale. You get variable pitch helis, but no real systems out there that suit my needs.

The idea of creating a fixed pitch propeller seems simple at first sight, find some propeller files, there's plenty of standardized propellers for a given pitch you can find online, then turn it into a CNC file and cut some wood or plastic for a prototype.

But then there's the Variable Pitch propeller which is the real milestone, and concerning their airfoils.

Airfoils on fixed props can be found online for a given pitch. Variable propellers change pitch by tilting the blade, my idea was thus to download or create a simple fixed pitch prop, then split it in the middle and install a mechanism which tilts the blade(using the same methodology helicopters use).

Would this concept make sense or are variable pitch propellers specifically designed to have a linear pitch in relation to their angles of attack, that is,
is there any fundamental difference between variable pitch props and fixed ones besides the mechanism which turns the blades?

To further elaborate: Assume two props with the same diameter had the same angle of attack, and the equal pitch for that angle, one being fixed and the other being variable, Would the airfoils be identical?
 
Engineering news on Phys.org
  • #2
Yes, variable pitch props still need to be twisted. The issue variable pitch solves is that as the plane speeds up, the angle of attack decreases, so at some point they produce no thrust. But they still have the same issue of different relative wind along the span due to the rotation. That's the reason for the twist.
 
  • #3
I saw variable pitch props used on solar powered models back in the 1990s in Switzerland. May still become info online. No battery was used. The pitch changed to keep the load on the cells at the optimum for the cell as light levels varied. So if you made a shadow with your hand on the cells the pitch changed. They were tricky to fly.
 

1. What is an airfoil of variable pitch propeller?

An airfoil of variable pitch propeller is a type of propeller that can change the angle of its blades while in motion. This allows for more efficient and precise control of the aircraft during flight.

2. How does an airfoil of variable pitch propeller work?

The angle of the blades on an airfoil of variable pitch propeller can be adjusted through a mechanism that is controlled by the pilot or an automated system. This changes the amount of thrust generated by the propeller, allowing for better performance and maneuverability.

3. What are the advantages of using an airfoil of variable pitch propeller?

An airfoil of variable pitch propeller offers several advantages over a fixed pitch propeller. It allows for better control and efficiency, especially during takeoff and landing. It also allows for a wider range of speeds and altitudes to be achieved.

4. What are the disadvantages of using an airfoil of variable pitch propeller?

The main disadvantage of an airfoil of variable pitch propeller is its complexity and cost. The mechanism for adjusting the blade angle adds weight and complexity to the propeller, making it more expensive to manufacture and maintain.

5. How is an airfoil of variable pitch propeller used in different types of aircraft?

An airfoil of variable pitch propeller is commonly used in aircraft that require precise control and high performance, such as military aircraft, helicopters, and some commercial aircraft. It is also used in small aircraft and drones for its efficiency and versatility.

Similar threads

  • Mechanical Engineering
Replies
2
Views
2K
  • Mechanical Engineering
Replies
8
Views
2K
Replies
2
Views
8K
  • Other Physics Topics
Replies
15
Views
4K
  • Aerospace Engineering
Replies
4
Views
11K
Replies
16
Views
5K
  • General Engineering
Replies
7
Views
2K
Replies
14
Views
3K
  • Mechanical Engineering
Replies
9
Views
1K
  • Classical Physics
Replies
30
Views
3K
Back
Top