Propellant Grain Stress And Strain

Propellant Dewetting

The objective of stress analysis of rocket motors is to design the configuration of the grain, the liners, or the grain support in such a way that excessive stresses or excessive strains will not occur and so that there will be no failure. Static and dynamic loads and stresses are imposed on the propellant grains during manufacture, transportation, storage, and operation. Structurally, a rocket motor is a thin shell of revolution (motor case) almost completely filled with a vis- coelastic...

Propellant Grain And Grain Configuration

Solid Propellant Grain Configuraton

The grain is the shaped mass of processed solid propellant inside the rocket motor. The propellant material and geometrical configuration of the grain determine the motor performance characteristics. The propellant grain is a cast, molded, or extruded body and its appearance and feel is similar to that of hard rubber or plastic. Once ignited, it will burn on all its exposed surfaces to form hot gases that are then exhausted through a nozzle. A few rocket motors have more than one grain inside a...

Turbopump Feed Systems And Engine Cycles

Flight Arc

The principal components of a rocket engine with one type of turbopump system are shown in the simplified diagram of Fig. 1-4. Here the propellants are pressurized by means of pumps, which in turn are driven by turbines. These turbines derive their power from the expansion of hot gases. Engines with turbopumps are preferred for booster and sustainer stages of space launch vehicles, long-range missiles, and in the past also for aircraft performance augmentation. They are usually lighter than...

Chemical Rocket Propulsion

Rocket Propulsion Flow Scheme

The energy from a high-pressure combustion reaction of propellant chemicals, usually a fuel and an oxidizing chemical, permits the heating of reaction product gases to very high temperatures 2500 to 4100 C or 4500 to 7400 F . These gases subsequently are expanded in a nozzle and accelerated to high velocities 1800 to 4300 m sec or 5900 to 14,100 ft sec . Since these gas temperatures are about twice the melting point of steel, it is necessary to cool or insulate all the surfaces that are exposed...

Conditions For 5000n Thrust

Thrust Stage Diagram

What is the ratio of the burning area to the nozzle area for a solid propellant motor with these characteristics Propellant specific gravity 1.71 Temperature sensitivity ap 0.007 (K)1 2. Plot the burning rate against chamber pressure for the motor in Problem 1 using Eq. 11-3 between chamber pressures of 11 and 20 MPa. 3. What would the area ratio Ab At in Problem 1 be if the pressure were increased by 10 (Use curve from Problem 2.) 4. Design a simple rocket motor for the conditions given in...

Propellant Processing And Manufacture

Casting Molds For Double Base Propellant

The manufacture of solid propellant involves complex physical and chemical processes. In the past, propellant has been produced by several different processes, including the compaction or pressing of powder charges, extrusion of propellant through dies under pressure using heavy presses, and mixing with a solvent which is later evaporated. Even for the same type of propellant e.g., double-base, composite, or composite double-base the fabrication processes are usually not identical for different...

Combinations of Ducted Jet Engines and Rocket Engines

Rocket Engine Fuel Tank

The Tomahawk surface-to-surface missile uses two stages of propulsion in sequence. The solid propellant rocket booster lifts the missile away from its launch platform and is discarded after its operation. A small turbojet engine sustains the low level flight at nearly constant speed toward the target. A ducted rocket, sometimes called an air-augmented rocket, combines the principles of rocket and ramjet engines it gives higher performance specific impulse than a chemical rocket engine, while...