Exhaust Velocity Given Thrust In Turbojet Calculator

Formula Used:

\[ V_e = \frac{T - A_e \times (p_e - p_{\infty})}{m_a \times (1 + f)} + V \]

Net Thrust of Turbojet (T):

Nozzle Exit Area (A_e):

m²

Nozzle Exit Pressure (p_e):

Ambient Pressure (p_∞):

Mass Flow Rate Turbojet (m_a):

kg/s

Fuel Air Ratio (f):

Flight Speed (V):

m/s

Exit Velocity (V_e):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Exhaust Velocity in Turbojet Engines?

Exit Velocity refers to the speed at which gases expand at the exit of nozzle of a turbojet engine. It is a critical parameter that determines the efficiency and thrust generation capability of the engine.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V_e = \frac{T - A_e \times (p_e - p_{\infty})}{m_a \times (1 + f)} + V \]

Where:

\( V_e \) — Exit Velocity (m/s)
\( T \) — Net Thrust of Turbojet (N)
\( A_e \) — Nozzle Exit Area (m²)
\( p_e \) — Nozzle Exit Pressure (Pa)
\( p_{\infty} \) — Ambient Pressure (Pa)
\( m_a \) — Mass Flow Rate Turbojet (kg/s)
\( f \) — Fuel Air Ratio
\( V \) — Flight Speed (m/s)

Explanation: This formula calculates the exhaust velocity by accounting for the net thrust, pressure differences at the nozzle, mass flow rate, fuel-air mixture, and the aircraft's flight speed.

3. Importance of Exhaust Velocity Calculation

Details: Accurate exhaust velocity calculation is crucial for determining engine performance, optimizing fuel efficiency, and designing propulsion systems for aircraft. It helps engineers understand how effectively the engine converts fuel energy into thrust.

4. Using the Calculator

Tips: Enter all values in appropriate units (thrust in Newtons, areas in square meters, pressures in Pascals, mass flow in kg/s, and speeds in m/s). All values must be positive numbers with fuel air ratio ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is exhaust velocity important in turbojet engines?
A: Exhaust velocity directly affects the thrust produced by the engine. Higher exhaust velocities typically result in greater thrust and better engine performance.

Q2: How does ambient pressure affect exhaust velocity?
A: Ambient pressure creates back pressure on the exhaust gases. Lower ambient pressure (at higher altitudes) allows for higher exhaust velocities and better engine performance.

Q3: What is the typical range of exhaust velocities for turbojet engines?
A: Typical exhaust velocities range from 400-800 m/s for subsonic aircraft and can exceed 1000 m/s for supersonic aircraft with afterburners.

Q4: How does fuel-air ratio affect exhaust velocity?
A: Higher fuel-air ratios generally increase the temperature and energy of the exhaust gases, which can increase exhaust velocity and thrust.

Q5: Are there limitations to this calculation?
A: This calculation assumes ideal gas behavior and may not account for all real-world factors such as friction losses, non-uniform flow, or complex nozzle geometries.