KiloNewton/Pound foot of thrust into Horsepower units

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Discussion Overview

The discussion revolves around converting engine thrust measurements from Kilo Newtons and Pound feet into Horsepower and Watts, particularly in the context of aviation engines compared to automotive engines. Participants explore the relationships between thrust, power, and the units used to measure them, while addressing the complexities involved in these conversions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants assert that thrust and power are fundamentally different quantities and cannot be directly converted without additional information about the propulsion system.
  • There is a claim that "pound foot" is not a recognized unit of thrust, and that "lbf" refers to pounds-force.
  • One participant mentions a formula for power as the product of thrust and velocity, emphasizing the need for velocity to determine useful output power.
  • Several participants note that the conversion from Watts to Horsepower is straightforward, with a commonly cited value of 746 Watts per Horsepower.
  • Some participants express confusion about the terminology used in specifications for jet engines, particularly regarding horsepower and its relation to different types of engines.
  • There is a discussion about the differences between turbojet, turbofan, turboprop, and turboshaft engines, particularly in how they report power and thrust.

Areas of Agreement / Disagreement

Participants generally agree that there is no direct conversion from thrust to horsepower due to the different nature of these measurements. However, there is disagreement regarding the terminology and the validity of certain units, particularly "pound foot" and how thrust is represented in various engine specifications.

Contextual Notes

Some participants highlight the importance of understanding the specific propulsion system when discussing thrust and power, indicating that assumptions about the type of engine can affect the discussion. There are also unresolved questions about the definitions and relationships between horsepower, thrust, and the specific context of aviation engines.

Who May Find This Useful

This discussion may be useful for students and professionals in aerospace engineering, mechanical engineering, and those interested in the comparative analysis of engine performance metrics.

  • #91
jbriggs444 said:
This appears to be word salad. Possibly you envision heating up a material to the point where its atomic nuclei and their component protons and neutrons spontaneously disassociate into a "plasma" of quarks. We cannot heat a meaningful quantity of material to such a temperature, cannot confine the resulting plasma, cannot use such a process to perform useful work and cannot cause any particular material to "precipitate out". The idea of the residue being reusable is not sensible since the energy inputs to the process would be huge and almost certainly unrecoverable.
Perhaps.
 
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  • #92
What are group's comment on Bell Boeing V-22 Osprey? I feel the aircraft design is quite sufficient to inspire a class of heli-crafts of near future for both passenger and cargo modes. Yet it is not much talked about.
 
  • #93
Arjun Singh said:
What are group's comment on Bell Boeing V-22 Osprey? I feel the aircraft design is quite sufficient to inspire a class of heli-crafts of near future for both passenger and cargo modes. Yet it is not much talked about.
What market would it be serving? If you are competing against turboprop craft, the ATR 72 is larger, cheaper, faster and has fewer crew.
 
  • #94
jbriggs444 said:
What market would it be serving? If you are competing against turboprop craft, the ATR 72 is larger, cheaper, faster and has fewer crew.
ATR 72 is a conventional fixed wing aircraft. I am talking about hybrid design of the Osprey. Aviation infrastructure, especially in emerging economies is concentrated towards major cities. Short Take-off/Vertical Take-off and landing aircrafts on the other hand do not require huge runways and thus can be served by airports with limited space and thus comparatively affordable infrastructure. Aircrafts like Osprey are basically made for defence purposes and here the operating costs are superseded by their unique field deployment capacities. A class of aircrafts built on such a platform for civilian use with comparative long haul and passenger capacities to their fixed wing counterparts, would surely consider low operating and maintenance costs as its prime design feature. Depending upon their application, these aircrafts can add an entirely new branch of premium and civil utility aviation infrastructure, to operate coordinatively alongside the present day high yield conventional infrastructure.
 
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  • #95
David Lewis said:
Unless it's massless, each quantum object does have its own gravitational field

Massless particles have a gravitational field too.

Cheers
 
  • #96
cosmik debris said:
Massless particles have a gravitational field too.

Cheers
Ain't these particles somehow part of gravity itself?
 
  • #97
Arjun Singh said:
Ain't these particles somehow part of gravity itself?

Ummm, no!

Cheers
 
  • #98
cosmik debris said:
Ummm, no!

Cheers
So how would you describe their quantum presence? Is their masslessness designates some sort of quantum threshold for energy to create mass?
What's your view?

Cheers!
 
  • #99
Arjun Singh said:
So how would you describe their quantum presence? Is their masslessness designates some sort of quantum threshold for energy to create mass?
What's your view?

Cheers!

I don't know what any of this means, sorry.

Cheers
 
  • #100
Arjun Singh said:
What are group's comment on Bell Boeing V-22 Osprey?
If you need an airplane with VTOL capability then the Osprey might be one to consider, but you will pay dearly for that capability.

Arjun Singh said:
Ain't these particles somehow part of gravity itself?
My understanding is a photon will warp spacetime because of its momentum.
 
  • #101
David Lewis said:
If you need an airplane with VTOL capability then the Osprey might be one to consider, but you will pay dearly for that capability.

My understanding is a photon will warp spacetime because of its momentum.
You mean by high fuel consumption due to VTOL?
 
  • #102
Poor fuel efficiency is only the tip of the iceberg.
 
  • #103
David Lewis said:
Poor fuel efficiency is only the tip of the iceberg.
What else?
 
  • #104
Mechanical complexity, low reliability, astronomical acquisition & operating cost, maintenance requirements, accident rate and pilot skill required.
 
  • #105
David Lewis said:
Mechanical complexity, low reliability, astronomical acquisition & operating cost, maintenance requirements, accident rate and pilot skill required.
Yet all these factors can be sorted out in the design upgrades of later class of VOTLs/STOLs. I believe Osprey's current design is good enough to inspire a whole new class of aircrafts without competing with conventional helicopters or fixed wing planes. A lot of its maintenance and handling complexities if any are I believe due to its unique use of twin turbo shafts which perhaps in future designs would become more integrated with the wing and fuselage, making the aircraft easier to operate.
 
  • #106
You're right. As technology advances, VTOL will become more competitive with conventional fixed wing.
 
  • #107
David Lewis said:
You're right. As technology advances, VTOL will become more competitive with conventional fixed wing.
I believe VTOLs will add to the vital side of aviation nomenclature of near future, let's say within a decade or so if I am not over stating. The reliability, frugality, handling parameters, usability and overall performance criteria of conventional fixed wing planes I don't think can be competed with in the traditional operational domains, at least not in foreseeable future.
 
  • #108
David Lewis said:
My understanding is a photon will warp spacetime because of its momentum.
Relativity equation states that energy of a particle is product of its mass and square of its velocity at the speed of light. At this state the particle mass simply converts to energy aligned to universal law of conservation of energy. To go beyond spacetime threshold a force has to be acting on the photon by virtue of its change in momentum or simply it needs to accelerate, p=mv or f=m(v2-v1) which is not possible in our dimension so thankfully spacetime would stay intact. Am i right?
 
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  • #111
This thread has veered a ways off-topic now, so it's a good time to tie it off. Thank you to all who contributed. :smile:
 

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