# Power and thrust relationship

### Thrust - Wikipedia

At constant average speed (v), a balance between thrust force (Ft) and drag force (Fd) should occur: Ft−Fd = 0; hence the power generated by. A very common question is how to contrast the thrust rating of a jet engine with the power rating of a piston. What is the differance between THRUST and POWER? For a jet aircraft, "thrust horsepower" is a function of static (0 airspeed) thrust and.

• Difference between Power and Thrust (Fixed Pitch Prop, Piston)
• Thrust vs Power
• Power vs Thrust (again)

During a race, a swimmer must be able to minimize the time spent in the starting phase, in the turning phases and in the stroking phases.

In these phases of the race the biomechanical determinants of performance are somewhat different than in the stroking phases; they will not be considered in this study.

Thus, at maximal clean swimming speed as well as in all conditions where average speed is constant and acceleration is nil a balance between thrust force Ft and drag force Fd should occur: As an example, rubber full body swimsuits allow a swimmer to reach larger speeds since, for a given power thrust a which characterizes a given swimmerthe power needed to overcome drag forces can be reduced [ 7 ]. These principles and considerations hold in all cyclic forms of locomotion; as an example, in cycling power output can be calculated either based on the resistive forces that the cyclist has to overcome e.

To estimate the trust force FtToussaint et al. The swimmer pulls the paddle and pushes his body forward; the propulsion force is measured by means of force transducers mounted on the paddles.

### Difference between Power and Thrust (Fixed Pitch Prop, Piston) | Ask a Flight Instructor

The major criticism of this method in measuring accurately Ft concerns the use of arms alone without considering the propulsion of the legs; thus the values of Ft are necessarily underestimated. Other researchers investigated the hand position during the pull phase of the stroke to determine the net force produced by the hand and the relative contribution of lift and drag vectors [ 10 ]. With the objective of solving this issue, the measurement of the pulling force during tethered or semi-tethered swimming was proposed as an alternative tool for evaluating Ft [ 12 — 13 — 14 — 15 — 16 ].

Despite the different reports in the literature about this method, after considering its advantages reliable and user-friendly and disadvantages for some authors the transferability to real swimming is debatabletethered swimming is the most frequently used method for determining the biomechanics profile of a swimmer [ 14 — 17 ]. A strong relationship between tethered force and swimmer's speed was indeed reported by several authors [ 14 — 18 ] even if the only reliable parameter for evaluating this relationship seems to be the average force of the all-out tethered [ 19 ].

The average force measured by the tethered method should then correspond to the useful, average, force to overcome water resistance at maximum speed [ 18 — 20 ]. Estimating the drag force Fd by means of passive towing experiments necessarily leads to an underestimation of the power needed to overcome drag forces since passive drag is lower than active drag [ 21 ].

## Can someone confirm this power to thrust relation?

The scientific discussion about the best method to assess active drag remains a controversial issue within the scientific community [ 28 ]. To estimate the active drag from passive towing, a procedure was proposed by Gatta et al. The aim of this study was to verify whether there is a balance between the power generated by thrust forces and the power needed to overcome drag forces in front crawl swimming by using a tethered test to assess Ft and Pt and by estimating active drag Fd, and hence Pd based on measures of passive drag at maximal speed.

We performed the experiments with the front crawl since its one of the strokes with the smallest intra-cyclic variations in speed and we decided to perform the experiments at maximal swimming speed to simulate the clean swimming speed during the stroking phase of a sprint race. Materials and Methods Participants Ten freestyle high-level male swimmers participated in this study The experiments were performed during the autumn ofwhen the swimmers were in their competition period.

All participants were non-smokers, and none of them was following specific dietary interventions. Essentially, for the same angle of climb, increasing the TAS velocity will increase the rate of climb directly. That's explained in more detail on the second image above. In a combustion engine, the power is related to the speed of the engine RPM.

## Power vs Thrust??

In the case of the airplane, power is related to the speed of the airplane. There is no difference in this relationship when comparing piston to jet performance. In the case of a propeller engine, the power is called "brake or shaft horsepower"; for an airplane, the power is called "thrust power" or typically "thrust horsepower" THP as it's generally displayed in units of horsepower.

The only difference happens because there is a difference in how a prop engine's thrust varies with TAS to how a jet's thrust varies with TAS. As for the prop engines, the thrust will decrease with increasing TAS because prop efficiency goes down. Eventually, the decrease in thrust overcomes the increase in TAS and you'll notice the THP curve will taper to zero and then decrease.

Now going back to Vx and Vy: Power-Producing Aircraft [ Dolepg.

In turbo-jets and other thrust-producing aircraft this thrust is produced directly from the engine. In aircraft that have propellers or rotorsthe engine does not produce thrust directly. These aircraft are called power producers because power turns the propeller. The propeller, in turn, develops an aerodynamic force when it is turned through the air; this force is thrust. Power producing aircraft have a flatter thrust required curve than thrust-producing aircraft; they can operate near the stall without requiring extremely high power settings.

Thrust-Producing Aircraft [ Dolepg.