Specific thrust?

Question

hi,

what is exactly the specific thrust?

I met it at an article, and be shown with a (s/m) unit (I guess, second/meter)...and some examples are given as:

westland lynx (heli) - 0.08

harrier is less than 0.01

osprey between 0.04 and 0.05

how can it calculated ?

Answer 1

It is net thrust/total intake airflow.  It gives you an idea of the total bulk of the engine.

For the Osprey and the Lynx, I think they are using the total airflow through the rotor/propeller discs.

Engines with low specific thrust are generally bulkier but quieter.

Military jet engines typically have high specific thrust.