THRUST AUGMENTATION

Aircraft thrust augmentation



Aircraft thrust augmentation

Introduction

Conventional rocket engines for a launch vehicle booster stage require consigning high thrust when taking off with the utmost vehicle heaviness, normally beside sea-level operation. They then function until coming to altitudes that have somewhat reduced ambient stresses round the engine.

The vehicle needs engines with as high exact impulse (Isp) as functional to minimize propellant mass; although, a high-vacuum Isp engine needs a large locality ratio nozzle. These two obligations confrontation since the large locality ratio nozzle functioning at sea-level force is less effective in making thrust. This is due to the gases over-expanding to a force underneath ambient. This outcomes in a piece of the nozzle developing contradictory thrust. At farthest locality ratios, the consume jet will distinct from the nozzle, initating large transient burdens and high localized heat fluxes, possibly impairing the nozzle. A variable locality nozzle would add complexity, cost, heaviness, and dimensions to the engine while still yielding less thrust at ocean grade than at vacuum.

 

TAN description

            Aerojet's patented TAN notion, shown in Fig. 1, overwhelms these accepted engine limitations by injecting propellants and combusting in an annular district inside the divergent part of the nozzle. This injection of propellants at moderate stresses permits for getting high thrust at takeoff without overexpansion thrust losses. The major sleeping room is functioned at a unchanging force while sustaining a unchanging head increase and flow rate of the major propellant pumps. Engine thrust augmentation larger than 100% of a usual engine is achievable.

Fig. 1. TAN design drawing for sea-level and high-altitude procedure modes.

 The notion is an elongation of the fluid oxygen (LOX)-augmented atomic thermal rocket (LANTR) , , , and , where LOX was injected into the divergent nozzle part of the superheated fluid hydrogen (LH2) consume of a atomic thermal rocket thrust sleeping room assembly (TCA) to combust with the hydrogen and develop added thrust. TAN takes the next step and injects both oxidizer and fuel into the divergent nozzle part of the TCA of a accepted bipropellant booster rocket engine where the lesser propellants blend and combust in the nozzle. This decreases expansion of the centre gases and rises nozzle pressure.

Fig. 2 displays a cross-section of a nozzle downstream of the throat with the fuel and oxidizer injection elements. Fig. 3 displays the axial force contour along the nozzle from throat to go out plane. This expanded nozzle force exactly directs to boost thrust. The ignition source for the lesser propellant is the warm consume from the centre engine gases.

Fig. 2. Schematic of TAN injection elements.

Fig. 3. Nozzle force as a function of axial expanse from major thrust sleeping room throat with and without TAN.

 

The TAN notion is scaleable to a broad variety of thrust -class engines from the very little thrust class of 2000 to 1,500,000 lbf and larger. The TAN notion is applicable to diverse engine cycle designs for example gas generator cycle, stage combustion circuits, and open and shut expander cycles.

The propellant blends that have been checked encompass gaseous oxygen (GOX) and LOX for ...