Rockets altitude

Altitude Testing of the Aerojet AJ-10-179 liquid Rocket Engine , AFRPL-TR-72-128... 

High-altitude sounding rocket (Height up to 160 km) 1000-2000 Skylark Single-stage vehicle. 

The air-intake used to induce air from the flight-altitude atmosphere plays an important role in determining the overall efficiency of ducted rockets. The air pressure built up by the shock wave determines the pressure in the ramburner. The temperature of the compressed air is also increased by the heating effect of the shock wave. The fuel-rich gaseous products formed in the gas generator burn with the pressurized and shock-wave heated air in the ramburner. The nozzle attached to the rear-end of the ramburner increases the flow velocity of the combustion products through an adiabatic expansion process. This adiabatic expansion process is equivalent to the expansion process of a rocket nozzle described in Section 1.2. 

A fixed fuel-flow system is a simple set-up that is operated to maintain a constant fuel-flow rate. The fuel-rich gas flows out from the gas generator through a choked orifice that is attached at its aft-end. The mass generahon rate of the fuel-rich gas is therefore independent of the pressure in the ramburner. When a projectQe operated by a fixed-flow ducted rocket flies at a constant supersonic speed and at constant altitude, the airflow rate through the air-intake remains constant. Since the gas generahon rate in the gas generator is kept constant, the air-to-fuel raho also remains constant. Ophmized combustion performance is thereby obtained. This class of ducted rocket is termed a fixed fuel-flow ducted rocket . 

In order to overcome the difficulties associated with the non-choked fuel-flow system and the fixed fuel-flow system, a variable fuel-flow system is introduced the fuel gas produced in a gas generator is injected into a ramburner. The fuel-flow rate is controlled by a control valve attached to the choked nozzle according to the airflow rate induced into the ramburner. An optimized mixture ratio of fuel and air, which is dependent on the flight altitude and flight velocity, is obtained by modulating the combustion rate of the gas-generating pyrolant When a variable fuel-flow-rate system is attached to the choked nozzle of the gas generator, the fuel-flow rate is altered in order to obtain an optimized combustible gas in the ramburner. This class of ducted rockets is termed variable fuel-flow ducted rockets or VFDR . 

Injection of species into the stratosphere associated with these launches includes emissions not only from the rocket exhaust but also from ablation of the solid rocket motors, the paint on the outer hulls, and hardware from satellites and discarded portions of rockets in the atmosphere (Zolensky et al., 1989). The increase in launches of such vehicles has led to a significant increase in particles associated with solid rocket use. Figure 12.10, for example, shows the concentration of large (>l-/xm diameter) solid stratospheric particles in the 17- to 19-km altitude region from 1976 to 1984,... 

M. Mochizuki, High-Altitude Combustion of Solid Propellant Rockets , KKK26 (4),... 

Tomlinson adopted another method, which, on the 11 whole, is more applicable to practice—namtdy, the do-, i termination of tho altitude of rockets, and which he l describee as being less liable to disturbances from colln- ... 

Figure 2. Variations in twilight lithium abundance at 80 km. altitude following the Teak and Starfish rocket explosions (16)...

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