The thrust coefficient (Ct) of a turbojet engine is a dimensionless parameter that characterizes the engine’s thrust performance by relating the actual thrust it produces to the engine’s operating conditions and design. It is calculated using the following formula:
Ct = (T / (P * Ae))
Where:
- Ct is the thrust coefficient (dimensionless).
- T is the actual thrust produced by the turbojet engine in newtons (N).
- P is the dynamic pressure of the incoming air at the engine inlet in pascals (Pa).
- Ae is the engine exhaust area in square meters (m²).
The thrust coefficient provides a standardized way to quantify and compare the thrust performance of turbojet engines across various operating conditions and design parameters. It is particularly useful for assessing how efficiently an engine converts incoming air’s dynamic pressure into thrust.
The dynamic pressure (P) represents the pressure associated with the motion of the air entering the engine and is calculated as 0.5 * ρ * V^2, where ρ is the air density and V is the airspeed.
The exhaust area (Ae) is the cross-sectional area at the engine’s nozzle exit, which affects the speed of the exhaust gases and, consequently, the thrust.
By calculating the thrust coefficient, engineers and researchers can evaluate the performance of turbojet engines in different situations and optimize engine designs for specific applications.