A jet-propelled aircraft traveling at 225 m / s takes in 50 kg / s of air. If the propulsive eff

step 1 In this equation, we have to find the propulsive efficiency and also find the speed at which the

A jet-propelled aircraft traveling at 225 m / s takes in 50...

A jet-propelled aircraft traveling at $225 \mathrm{m} / \mathrm{s}$ takes in $50 \mathrm{kg} / \mathrm{s}$ of air. If the propulsive efficiency (defined as the ratio of the useful work output to the mechanical energy input to the fluid) of the aircraft is 45 percent, determine the speed at which the exhaust is discharged relative to the aircraft.

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Propulsive Efficiency

This concept measures the effectiveness of a propulsion system by comparing the useful work output (typically the thrust acting on the vehicle) to the total mechanical energy input into the fluid. It is crucial for understanding how much of the input energy is successfully converted into the kinetic energy that propels the vehicle.

Energy Conversion in Propulsion Systems

Energy conversion involves transforming stored energy into kinetic energy through the expulsion of mass. In propulsion, this conversion is quantified by assessing how fuel energy is transferred into the kinetic energy of the exhaust, which in turn produces thrust.

Mass Flow Rate

Mass flow rate is the amount of mass passing through a given cross-sectional area per unit time. It plays a key role in propulsion calculations because the rate at which mass is accelerated directly influences the momentum change and therefore the thrust generated by the engine.

Relative Velocity

Relative velocity refers to the speed of the exhaust relative to the aircraft. Understanding this concept is essential in propulsion because it determines the effective difference in speed that produces thrust, highlighting the importance of analyzing motion from different reference frames.

Transcript

Please give Ace some feedback