# Talk Turbines: Converting Newtons Thrust to Watts

• willib
In summary: It should be producing something like 700 hp/ton.In summary, the relationship between hp and thrust is not linear, and there is more to it than just thrust at a given speed equating to a given hp.
willib
Last edited:
Jet engines have a thrust horsepower calculation, but I don't think it could be held applicable in this case. The rule is at 375 mph, 1 Lbf of thrust is equal to 1 HP.

These Wren turbines are just under three inches in diameter..
very cool stuff..

Hey Fred, that works out, because if you say an aircraft is flying at 375 mph and that aircraft requires 1 lbf of thrust to keep it going at that speed, the power (force times distance per unit time) works out to 1 hp. But that's an arbitrary velocity. If the aircraft has more resistance, and can only fly at 100 mph with the same engine, then the equation results in a power output of 0.2667 hp. And if it's zipping along at 1000 mph, the power output becomes 2.667 hp.

So there doesn't seem to be a correlation between hp and thrust. But there should be since the power actually equates to energy in (ie: energy burned in the engine).

I always wondered about this one, how can you equate thrust to hp? Perhaps because it's "static thrust" one must be able to get a "thrust curve" which is analogous to a pressure curve on a centrifugal pump, along with an efficiency.

There has to be more to it than simply thrust at 375 mph equates to a given hp.

Q_Goest said:
Hey Fred, that works out, because if you say an aircraft is flying at 375 mph and that aircraft requires 1 lbf of thrust to keep it going at that speed, the power (force times distance per unit time) works out to 1 hp. But that's an arbitrary velocity. If the aircraft has more resistance, and can only fly at 100 mph with the same engine, then the equation results in a power output of 0.2667 hp. And if it's zipping along at 1000 mph, the power output becomes 2.667 hp.

So there doesn't seem to be a correlation between hp and thrust. But there should be since the power actually equates to energy in (ie: energy burned in the engine).

I always wondered about this one, how can you equate thrust to hp? Perhaps because it's "static thrust" one must be able to get a "thrust curve" which is analogous to a pressure curve on a centrifugal pump, along with an efficiency.

There has to be more to it than simply thrust at 375 mph equates to a given hp.

You do bring up good points. Personally I have NEVER expressed a thrust producing engine in terms of horsepower. It is always in thrust. For some (unknown to me) reason there is a small need to express HP in this fashion. The relationship $$THP = \frac{F_n * MPH}{375}$$ is actually from a Pratt and Whitney reference I have. It is the only reference I have that even states it. What it's method of derivation is I really do not know.

Oops my mistake..

FredGarvin said:
The relationship $$THP = \frac{F_n * MPH}{375}$$ is actually from a Pratt and Whitney reference I have. It is the only reference I have that even states it. What it's method of derivation is I really do not know.
As I understand it, hp:thrust ratio depends on not only speed, but also altitude. I assume that it has something to do with factoring in air resistance.
It always bugs me that a full-throttle jet bolted to a test stand produces zero horesepower.

## 1. What is the purpose of converting Newtons thrust to Watts for turbines?

The conversion from Newtons thrust to Watts is necessary to understand the power output of a turbine. Watts is a unit of power, which measures the rate at which energy is transferred or used. By converting the thrust of a turbine, we can determine its power output and efficiency.

## 2. How is the conversion from Newtons thrust to Watts calculated?

The conversion is calculated by multiplying the force of Newtons thrust by the velocity at which it is produced. This is represented by the formula P = F x V, where P is power in Watts, F is force in Newtons, and V is velocity in meters per second.

## 3. What factors affect the conversion from Newtons thrust to Watts for turbines?

The conversion can be affected by several factors, including the size and design of the turbine, the type of fluid or gas used, and the efficiency of the turbine. The efficiency of a turbine can vary depending on its operating conditions, such as temperature and pressure.

## 4. How does the conversion from Newtons thrust to Watts impact the performance of a turbine?

The conversion is directly related to the power output of a turbine. A higher power output means the turbine is able to generate more energy, making it more efficient. Therefore, understanding the conversion from Newtons thrust to Watts is crucial in optimizing the performance of a turbine.

## 5. Can the conversion from Newtons thrust to Watts be used for all types of turbines?

Yes, the conversion can be applied to all types of turbines, including steam turbines, gas turbines, and wind turbines. However, the specific formula and factors may vary depending on the type of turbine and its operating conditions.

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