Laser thermal rocket engines are theoretical propulsion systems that involve the use of directed energy from lasers to heat a propellant, typically a working fluid such as hydrogen. The heated propellant is then expelled through a rocket nozzle to generate thrust.
For laser thermal rocket engines, factors such as the laser power, absorption efficiency, heating and expansion of the propellant, and nozzle design influence the specific impulse. Additionally, the nature of laser thermal propulsion involves external energy sources, making the calculation more complex than traditional rocket engines.
It is defined as the thrust generated per unit of propellant expended and is expressed in seconds.
where,
- is the specific impulse of the rocket engine (in seconds, s)
- F is the Thrust Produced
- ṁ is the mass flow rate of propellant in KG/Sec
- g0 is the acceleration due to gravity