Propeller blade lift distribution for best thrust/power ratio?

Click For Summary

Discussion Overview

The discussion revolves around the ideal lift distribution for propeller blades to achieve the best thrust-to-power ratio. It explores various factors influencing propeller design, including drag, torque, and the specific applications of different types of propellers.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about the ideal lift distribution for propeller blades, emphasizing the relationship between drag, torque, and power.
  • Another participant asks for clarification on the type of propeller (e.g., helicopter, low-speed personal aircraft, high-speed turboprop) and the operational parameters such as size, altitude, and airspeed.
  • Some participants suggest that modern propellers are optimized for their intended use, yet acknowledge that they vary significantly.
  • A participant asserts that there is no single answer to the question and suggests that a comprehensive understanding requires a textbook on propeller design.
  • One participant reiterates that while size is dependent on thrust requirements, it is not central to the inquiry about lift distribution.
  • Another participant recommends searching for optimal aircraft propeller design resources, providing a link to a relevant article.
  • A later reply emphasizes the importance of clearly specifying the problem as a first step in engineering design.

Areas of Agreement / Disagreement

Participants express differing views on the existence of a singular optimal lift distribution and the necessity of specific parameters for propeller design. The discussion remains unresolved with multiple competing perspectives on how to approach the question.

Contextual Notes

Participants highlight the complexity of propeller design, indicating that assumptions about optimality may depend on specific conditions and applications. There is an acknowledgment of the need for detailed specifications to address the inquiry effectively.

John Mcrain
Messages
435
Reaction score
28
What is ideal lift distribution for propeller blade to get best thrust/power ratio?

To do this blade must has minimum drag, because drag releted to torque,and torque x RPM= power..
 
Physics news on Phys.org
Good question. What kind of propeller blade? (helicopter, low-speed personal aircraft, high-speed turboprop, etc.) What size of propeller? Over what range of altitudes and airspeeds?
 
I would assume that every modern propeller made by propeller companies is optimal for the range of parameters specified. But they are not all alike.
 
  • Like
Likes   Reactions: russ_watters and berkeman
berkeman said:
Good question. What kind of propeller blade? (helicopter, low-speed personal aircraft, high-speed turboprop, etc.) What size of propeller? Over what range of altitudes and airspeeds?
low speed propeller,let say at 150km/h...

Size depends on how much thrust do I need, but it is irrelevant for my question because I ask in general for best lift distribution..
 
There is no single answer. You are asking for a formula or a curve when what you need is a textbook on propeller design.
 
John Mcrain said:
Size depends on how much thrust do I need, but it is irrelevant for my question because I ask in general for best lift distribution..
1612738261123.png

https://i.ytimg.com/vi/uOHckOudGGQ/maxresdefault.jpg

Versus:
1612738338468.png

https://hartzellprop.com/wp-content/uploads/Voyager-Propeller.jpg

Versus:
1612738382715.png

https://hartzellprop.com/wp-content/uploads/Cessna-177B.jpg
 
Engineering Step 1: Specify the problem.
 
  • Like
Likes   Reactions: Tom.G

Similar threads

Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
6K
Replies
2
Views
4K
Replies
9
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 17 ·
Replies
17
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 62 ·
3
Replies
62
Views
31K