Ad
related to: thrust available vs required value of current energy ratespowersetter.com has been visited by 10K+ users in the past month
Search results
Results from the WOW.Com Content Network
If the energy is produced by the mass itself, as in a chemical rocket, the fuel value has to be /, where for the fuel value also the mass of the oxidizer has to be taken into account. A typical value is v e {\displaystyle v_{\text{e}}} = 4.5 km/s, corresponding to a fuel value of 10.1 MJ/kg.
The aft-fan fitted to the General Electric CJ805-3 turbojet augmented the take-off thrust from 11,650lb to 16,100lb. Water, or other coolant, [ 16 ] injection into the compressor or combustion chamber and fuel injection into the jetpipe ( afterburning /reheat) became standard ways to increase thrust, known as 'wet' thrust to differentiate with ...
The engine does work on the air going through it and this work is in the form of an increase in kinetic energy. The increase in kinetic energy comes from burning fuel and the ratio of the two is the thermal efficiency which equals increase in kinetic energy divided by the thermal energy from the fuel (fuel mass flow rate x lower calorific value).
Aircraft engine performance refers to factors including thrust or shaft power for fuel consumed, weight, cost, outside dimensions and life. It includes meeting regulated environmental limits which apply to emissions of noise and chemical pollutants, and regulated safety aspects which require a design that can safely tolerate environmental hazards such as birds, rain, hail and icing conditions.
Since the power equals thrust times speed, the efficiency is given by = / where V is speed and h is the energy content per unit mass of fuel (the higher heating value is used here, and at higher speeds the kinetic energy of the fuel or propellant becomes substantial and must be included).
For example, LH 2 /LO 2 bipropellant produces higher I sp (due to higher chemical energy and lower exhaust molecular mass) but lower thrust than RP-1/LO 2 (due to higher density and propellant flow). In many cases, propulsion systems with very high specific impulse—some ion thrusters reach 25x-35x better I sp than chemical engines—produce ...
Propulsive efficiency is defined as the ratio of propulsive power (i.e. thrust times velocity of the vehicle) to work done on the fluid. In generic terms, the propulsive power can be calculated as follows:
A rocket is propelled forward by a thrust equal in magnitude, but opposite in direction, to the time-rate of momentum change of the exhaust gas accelerated from the combustion chamber through the rocket engine nozzle. This is the exhaust velocity with respect to the rocket, times the time-rate at which the mass is expelled, or in mathematical ...
Ad
related to: thrust available vs required value of current energy ratespowersetter.com has been visited by 10K+ users in the past month