JRP Finals PDF

JRP FINALS Study online at https://quizlet.com/_g86ogr its primary function is to channel and accelerate the combustion products produced by the burning propellant in such a way as nozzle...

JRP FINALS Study online at https://quizlet.com/_g86ogr its primary function is to channel and accelerate the combustion products produced by the burning propellant in such a way as nozzle to maximize the velocity of the exhaust at the exit, to supersonic velocity Accomplishes the primary function of a nozzle by varying the convergent-divergent rocket nozzle cross-sectional area in an exacting form. De Laval nozzle another name for convergent-divergent rocket nozzle they are pushed from combustion into the throat region of the exhaust gases nozzle it has a smaller cross-sectional area than the rest of the engine, throat where gases are compressed to high pressure the nozzle gradually increases in cross-sectional area allowing thrust gases to expand and push against the walls creating ________. the nozzle converts _________ of hot chamber gases into thermal energy, kinetic energy _________ and direct that energy along the nozzle axis the flow of the fluid (exhaust gases + condensed particles) is constant ______ during the burn one-dimensional flow when the direction of the flow is along a straight line axis of symmetry it is where the flow of a nozzle is assumed to be A ________ fluid exhibits significant changes in density, while a compressible, incompressible _________ fluid does not. it allows the use of direct relationship between pressure, density, ideal gas and temperature, which are properties that are particularly impor- tant in analyzing flow through a nozzle change in cross-sectional area [enumerate] fluid properties, such as velocity, density, pressure, friction and temperature, in compressible fluid flow, are affected by: heat loss to the surroundings The goal of rocket nozzle design is to accelerate the combustion products to as high an exit velocity as possible. This is achieved isentropic flow by designing the necessary nozzle geometric profile with the condition that _______ is to be aimed for. a flow that is dependent only upon cross-sectional area, which isentropic flow necessitates frictionless and adiabatic flow energy continuity [enumerate] equations for the analysis of compressible fluid flow momentum the equation of state it comprises the internal thermal energy plus the flow work; can enthalpy be expressed as the product of the specific heat and the absolute temperature energy equation it is a statement of the principle of conservation of energy it is the mathematical form of the principle of conservation of mass continuity equation in a steady flow the properties that would result if the fluid were isentropically stagnation properties declared to zero velocity a dimensionless flow parameter used to define the ratio of the flow mach number velocity to the local acoustic velocity conical bell/contoured [enumerate] nozzle configurations annular the oldest and simplest configuration among different rocket en- conical nozzles gines because of its ease to fabricate; the walls of the nozzle diverge at a constant angle 1/5  JRP FINALS Study online at https://quizlet.com/_g86ogr similar to conical design but aer more efficient and more compact; its shape provides an advantage for it minimizes the turning di- bell/contoured nozzle vergence losses; designed such that all waves are isentropic and produce a nearly axial flow at the nozzle exit the least employed among the nozzle configuration due to its annular nozzle greater complexity; combustion occurs along a ring, around the base of the nozzle expansion-deflection reverse-flow [enumerate] radial out flow annular nozzles horizontal-flow works similar to a bell nozzle, since the exhaust gases are forced into a converging throat region of low area before expanding in a expansion-deflection nozzle bell-shaped nozzle; the flow is deflected by a plug that forces the gases away from the center of the nozzle the fuel is inject from underneath, but the exhaust gases are reverse-flow nozzle rotated 180º horizontal-flow nozzle the fuel is inject sideways, but the exhaust is rotated 90º spike [enumerate] radial in flow annular nozzles linear-aero-spike spike nozzles a type of nozzle named for the prominent spike center body a nozzle configuration removing the pointed spike and replacing it truncated aerospike nozzles with a flat base Heat transfer analysis require the determination of the ______, specific heats, thermal conductivity, specific heat ratio _______, and ________. it usually occurs in the combustion chamber at essentially con- combustion process stant chamber pressure it is when the fully reacted, equilibrated gas combustion products nozzle gas expansion process enter the nozzle and undergo an adiabatic expansion in the nozzle it states that a mixture of gases at equilibrium exerts a pressure Dalton's Law that is the sum of the partial pressures of the individual gases, all at the same temperature For rockets using H2 and O2 propellants, the best operating 4.5, 6.0, 8.0 mixture mass ratio for high performance rocket engines is typically between ___ and ___, not at the stoichiometric value of ___. it exists in reversible chemical reactions when the rate of forming chemical equilibrium products is exactly equal to the reverse reaction of forming reac- tant from the products type of rocket where the propellant is contained and stored directly solid propellant rocket motors in the combustion chamber, sometimes hermetically sealed in the chamber for long-time storage. the word _____ is as common to solid rockets as the word _____ motor, engine is to liquid rockets it is the solid body of the hardened propellant and typically ac- grain counts for 82-94% of the total motor mass this provides the energy to start the combustion (electrically acti- igniter vated) In a grain configuration that has a central cylindrical cavity with 8-pointed star eight tapered slots, the burning will form an _____ the hot reaction gases flow along the _____ or ______ toward the perforation, port cavity nozzle It acts as the thermal protection of the inner surfaces of the case insulation layer to keep the case from being too hot metal, composite fiber the case is either made of _____ or _____-reinforced plastic 2/5  JRP FINALS Study online at https://quizlet.com/_g86ogr the _____ accelerates the hot gas; it is made of high temperature nozzle materials to withstand the high temperatures and the erosion cartridge-loaded [enumerate] two methods of holding grain in the case case-bonded they are manufactured separately from the case and then loaded into or assembled into the case; used in some small tactical cartridge-loaded grains missiles and a few medium-sized motors; lower cost and easier to inspect the case is used as a mold and the propellant is cast directly into the case and is bonded to the case or case insulation; gives better case-bonded grains performance, less inert mass, better volumetric loading fraction, often somewhat more difficult and expensive to manufacture they can more easily be replaced if the propellant grain has aged freestanding grains excessively flight mission grain geometry propellant [enumerate] interrelated requirements a grain has to satisfy structural integrity internal cavity volume processing from here, one can determine the rocket motor requirements. they flight mission have to be defined and known before the grain can be designed it is selected to fit these requirements: it should be compact and sue the available volume efficiently, have an appropriate burn grain geometry surface versus time profile to match the desired thrust-time curve, and avoid or predictably control possible erosive burning. it is usually selected on the basis of its performance capability, propellant mechanical properties, ballistic properties, manufacturing charac- teristics, exhaust plume characterisitcs, and aging properties this must be analyzed to assure that the grain will not fail in stress structural integrity or strain under all conditions of loading, acceleration, or thermal stress it increases with burning time and needs to be checked for reso- internal cavity volume nance, damping, and combustion stability a grain requirement regarding fabrication; should be simple and processing low cost they form homogeneous propellant grain; both the major ingredi- double-base (db) propellants ents are explosives and function as a combined fuel and oxidizer extruded double-base (edb) cast double-base (cdb) cast-modified double-base (cmdb) [enumerate] double-base propellant modifications elastomeric-modified cast double-base (emcdb) composite-modified double-base (cmdb) they form a heterogeneous propellant grain with the oxidizer crys- compositie propellants tals and a powdered fuel held together in a matrix of synthetic rubber binder made by mechanical mixing of solid and liquid ingredients, fol- cast propellant lowed by casting and curing; it is most common process for com- posite propellants extruded propellant made by mechanical mixing followed by extrusion it is what a liquid propellant rocket propulsion system is commonly rocket engine called it is the combustion device where the liquid propellants are me- thrust chamber/thruster tered, injected, atomized, mixed, and burned to form hot gaseous 3/5 JRP FINALS Study online at https://quizlet.com/_g86ogr reaction products, which in turn are accelerated and ejected at a high velocity to impart a thrust force injector combustion chamber [enumerate] 3 major parts of a thrust chamber nozzle its two principle functions are to raise the pressure of the propel- feed systems lants and to feed them to one or more thrust chambers they are the working substance of rocket engines, constituting the propellants fluid that undergoes chemical and thermodynamic changes it has two separate liquid propellants, and oxidizer, and a fuel. they bipropellant are stored separately and are not mixed outside the combustion chamber it contains an oxidizing agent and combustible matter in a single monopropellant substance; may be a mixture of several compounds or it may be a homogeneous material, such as hydrogen peroxide or hydrazine it is stored at very high pressure, gives a low performance, allows cold gas propellant a simple system and is usually very reliable. it is a liquified gas at low temperature, such as oxygen or liquid cryogenic propellant hydrogen they are liquid at ambient temperature and can be stored for long storable propellants periods in sealed tanks it is a thixotropic liquid with a gelling additive; it behaves like a jelly gelled propellant or thick paint corrosion explosion hazards fire hazards [enumerate] common physical hazards of propellants accidental spills health hazards material compatibility low freezing point high specific gravity stability [enumerate] desirable physical properties of propellants heat transfer properties pumping properties temperature variation liquid oxygen (O2) hydrogen peroxide (H2O2) [enumerate] common liquid oxidizers nitric acid (HNO3) nitrogen tetroxide (N2O4) it is widely used as an oxidizer and burns with a bright white-yellow liquid oxygen (O2) flame with most hydrocarbon fuels in rocket application, it has been used in a highly concentrated form of 70-99%; even under favorable conditions, it will often hydrogen peroxide (H2O2) decompose at a slow rate during storage and gas will bubble out of the liquid nitric acid (HNO3) it is the most common type of oxidizer it is a high-density yellow-brown liquid, storable propellant oxidizer nitrogen tetroxide (N2O4) and is used together with a fuel mixture consisting of hydrazine and unsymmetrical dimethylhydrazine it is a rocket propulsion concept in which one component of the hybrid propellant rocket propellant is stored in liquid phase while the other is stored in solid phase hybrid propellant rockets commonly employ ______ oxidizer and liquid oxidizer, solid fuel _____ fuel 4/5  JRP FINALS Study online at https://quizlet.com/_g86ogr it is well suited to applications or missions requiring throttling, command shutdown and restart, long-duration missions requir- hybrid propulsion ing storable nontoxic propellants, or infrastructure operations that would benefit from a non-self-deflagrating propulsion system in cryogenic systems, this implies a high level of compressibility from sources such as vapor cavities or two-phase flow in feed oxidizer feed system-induced instability (non-acoustic) lines combined with insufficient isolation from motor combustion processes; essentially a chugging type and arises when the feed is sufficiently soft it was first observed during the development of solid fuel ramjets; flame holding instability (acoustic) typically manifested at acoustic frequencies and appear in longi- tudinal modes 5/5