Propellant grain design considerations in software

Design and structural analysis of solid rocket motor casing hardware used in aerospace applications. A grain is any individual particle of propellant regardless of the size or shape. An effective design of solid propellant grains mostly depends on the. Finocyl grain design using the genetic algorithm in combination. Further calculations and ne tuning of the geometry can then be done using the current software models. The primary function of a propellant grain is to produce combustion products at a prescribed flowrate defined by. Considerations for designers of cases for small solid propellant rocket motors. Design and geometrical analysis of propellant grain.

Yet, it does not provide fast analysis or a basis for optimizations of the propellant geometry, also known as the grain geometry. The design process involves parametric modeling of the geometry in catia software through dynamic. Here is a typical bates grain the outside surface of a bates grain is inhibited so it wont burn, leaving the. Should the propellant grain develop a crack, for example, ignition would cause combustion to take place in the crack, with explosion as a possible result. Propellant grain article about propellant grain by the. Propellant grain and grain configuration chamber pressure. Proposal for the inclusion of kno3sugar propellants to tra, october 4, 2002 page 4.

Design and structural analysis of solid rocket motor casing. This model will only examine a few aspects of the performance of a srm. Each propellant segment can be of a different propellant type. The grain behaves like a solid mass, burning in a predictable fashion and producing exhaust gases. A solid propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants fueloxidizer.

Hybrid propellant motor design amazon web services. A numerical method for solid propellant grain design article. The morphological continuum in solid propellant grain design. The work presented deals with the application of the ptc creo software tool for design of any arbitrary solid form of a rocket motor propellant grain. First of all, with the help of geometry constraint solver, the fuzzy concept of grain configurations can be converted to a geometric. A propellant editor that allows the user to configure as many propellants as they want. Full text of solid propellant processing factors in rocket motor. The software produces estimates of a rocket motors chamber pressure and thrust based on input such as propellant properties and grain geometry. Abstract rocket motors are widely used to generate thrust or impulsive force to impart a desired velocity to flight vehicle to transport its payload to the intended destination. Design, analysis, and simulation of rocket propulsion system.

During the past 20 years, requirements on performance, reliability and cost of solid propellant rocket motors and also on schedules and cost of development have become more and more stringent. So the most important step in designing the solid propellant rocket motor is determination of the geometry of the solid propellant grain. The company also contracts to perform engineering analyses for the us defense and space agencies, and for many leading companies in the aerospacedefense industry. This is known as a strandburner test, because the propellant sample is a strand. Design and geometrical analysis of propellant grain configurations of a solid rocket motor 1patan stalin, 2y. Figure 41 three solid propellant grains shown in isometric and front view diagrams. Southwest missouri state university, 1998 a thesis submitted in partial fulfillment of the requirements for the degree of master of science in the department of mechanical, materials, and aerospace engineering. The propellant material and geometrical configuration of the grain determine the motor performance characteristics. Pdf additive manufacturing of solid rocket propellant grains. Full transient burnback include ignitor mass flow, and engine filling and blowdown. Elastomeric thermal insulation design considerations in long, aluminized solid rocket motors heath t. It uses the fast marching method to determine how a propellant grain regresses, which allows the use of arbitrary core geometries.

Even cracks can easily be drawn with a drawing program, and modeled. The nozzle dimensions are calculated to maintain a design chamber pressure, while producing thrust from the exhaust gases. Another consideration for choosing design variables is quantity of. The dependence of the coordinate of the point at which the metal particle leaves the grain surface on the initial size of the particle burning out at the channel outlet was given in the paper 7. Request pdf solid propellant grain design and burnback simulation. Design and structural analysis of solid rocket motor. Abstract design and analysis of propellant grain configurations for determination of the grain geometry which is an important and critical step in the design of solid propellant rocket motors, because accurate calculation of grain geometrical properties plays a vital role in performance prediction. Hybrid propellant motor design kent evans, chris ryan, sam heyd, danny cha, johnny wang 22315 1. Fuel grain overall length oxidizer tank size dependent on overall weight. Solidrocketmotor performancematching design framework. This is due to the flow velocity through the fuel port being equal to the velocity through the nozzle throat.

The program aids in unifying the nozzle, chamber and injector portions of a rocket propulsion system design effort quickly and efficiently using a streamlined graphical user interface gui. Design optimization of solid rocket motor grains for internal ballistic performance by r. Composite propellant grain geometries were additively manufac. Develop, design, and demonstrate potential alternatives for a sensor system to detect cracking in a propellant grain and transmit the sensor data through a hermetically sealed rocket case. Perform an analysis of alternatives and demonstrate feasibility of selected approach. When performing a solid propellant grain design analysis, two levels of design accuracy have to be distinguished. Design and manufacture closely mirrored the four main segments. Full text of solid propellant processing factors in rocket. Also, the revision reorganizes the material and presents the design information in a more logical sequence. The propellant grains we are going to make are called bates grains, a bates grain is cylindrical, with a hole core running through the center of the cylinder. Optimized solid propellant manufacturing through 3d. This dynamic balance is defined by using a linear variation known as st. Aeroisp is a solid rocket motor srm internal ballistics computer program that assumes the rate of combustion of the burning gases are in dynamic equilibrium with the rate at which the exhaust gases are expelled out the nozzle. If the propellant has lowenergy additives fuel rich or lowenergy effects chemicals, a higher kn 240 or higher may be required.

Internal ballistics simulation of a solid propellant rocket motor. Kno3 based sugar propellants sp have been utilized in experimental rocketry for many years. A constitutive model of the solid propellants considering. Army researchers have invented a process to produce a grain geometry that will result in a constant pressure in a gun or rocket over the ballistic cycle. In view of this we have undertaken a detailed comparative study of network forming agents in the composite solid rocket propellant formulation htpb. Design and structural analysis of solid rocket motor casing hardware used in aerospace applications b. The propellant grain is a cast, molded, or extruded body and its appearance and feel is similar to that of hard rubber or plastic. Solely for cylindrical grain configurations, such as bates. Core geometry can also be loaded from a dxf file for custom grains. Ae6504 propulsion ii, third year, department of aeronautical. If a propellant is comprised of two constituents, and oxidizer and a fuel, the ideal density is given by.

Depending on the fuel and propellant mixture used and with hybrid rocket stages that use solid fuels, some of the common ones seem adhesive enough to enable additive manufacturing techniques a. Advances in solid rocket nozzle design and analysis technology in the united states since 1970. The handbook is a guide to design engineers engaged in the development of propellant actuated thrust devices and gas generators for various applications. The spp12 nozzle module analyzes and summarizes the performance loss mechanisms into four categories. Roberts law between the rate at which the propellant surface recedes r and the chamber. Both spreadsheets and commercial software are used.

Three dimensional modified star grain design and burnback analysis. There is a lot of useful configuration and they should be evaluate in order to decide which one to use in particular situations. A unique, threepart undergraduate gas turbine engine design project was developed to acquaint students, working in teams of two or three, with the process of engine cycle selection. Generally, no propellant grain manufactured or designed with conventional means entirely exploits the potential available from the barrel design limit.

Inflight propellant transfer spaceplane design and testing. A solid propellant rocket motor propellant grain configuration having a center bore of a varying diameter, ballistic slots, a stressballistic groove, and a burn inhibitor band for withstanding service motor operating environments and providing the required ballistic profile. In a nutshell, input your motor, nozzle and propellant characteristics and burnsim calculates the kn through the burn and predicts estimated chamber pressure and motor performance. In order to design solid rocket grain configuration intuitively and accurately, this paper introduces a 3d feature design method based on the variational design technology which is popular in the field of mechanical product computer aided design. In addition, the book includes a section on mechanical properties of solid propellant grains, essentially as a subject in its own right, but partly for its practical connection with internal ballistic design and hence with combustion.

Internal ballistics simulation of a solid propellant rocket motor marc faria gomes disserta. The tools used at this level must be simple and friendly enough to be operated by propellant grain project managers themselves. A grain editor that shows how the propellant regresses as the user changes parameters. It is difficult to finalize one of these without considering all others, and there may be several iterations of each. This document details the functionality of a software program used to streamline a rocket propulsion system design, analysis and simulation effort. Grain design program lite gdp is capable of calculating all 2dgrains, like stars, moonburners, slotted grains, and bates grains. Design considerations two phase flow combustion stability hole diameter hole inlet geometry. Tabular input allows grain input by entering burning area and burning volume as function of burn depth. The earliest rockets were solidfuel rockets powered by gunpowder. Nowadays, cad software programs are used for modeling and drafting the grain geometry 4, 9, 10,11,12. Optimization of network forming agents for different types of. We created and modify 2d star grain to be burned as 3d star grain by. These propellants were some of the earliest available and have been well characterized through the contributions of many individuals.

The processing of the grain and the fabrication of the propellant should be simple and low cost see chapter 12. The grain configuration is designed to satisfy most requirements, but sometimes some of these six categories are satisfied only partially. Spp includes additional 3d grain design and 1d motor ballistics modules. Propellant transfer, on the other hand, can be certified by slowly and incrementally flying formation, then near the tanker, then in dry contact with the tanker, then with increasing amounts of propellant transfer, opening the envelope in a very gradual fashion. Grain configurations for solid propellant rockets are classified by relative web thickness and mean vector direction of burning surface into a topological continuum. This, in turn, has a direct effect on solid propellant grain design methods and procedures, and on development program content. Xrayed to ensure that the propellant grain is homogeneous, bonded everywhere to the case, and free of cracks. Choosing the grain geometry is the primary way to control the overall kn curve for a motor design. Once ignited, it will burn on all its exposed surfaces to form hot gases that are then exhausted through a nozzle. Solid propellant grain design and burnback simulation using a. A complete discussion on burn rate is provided in the propellant burn rate web page.

Solid propellant grain design and internal ballistics. In continuous mixing, the same propellant ingredients are continuously measured into a mixing chamber, mixed, and continuously discharged into the motor or other container until the required amount of propellant has been obtained. Now we will introduce a model for the source of the hot gases in solid propellant rockets. Solid propellant rocket research progress in astronautics. Motor performance data is also summarized for easy input into a trajectory simulation software, such as soar.

In his online article on propellant grain theory, richard nakka cautions that severe core stripping is likely to occur if the ratio of port area to throat area reaches one. The rate at which this propellant burns down the strand is measured to determine the propellant burn rate. Solid propellant grain geometry design, a model for the. A numerical method for solid propellant grain design. Grain designs we have thus far discussed two models for the nozzle flow in rocket engines, the channel flow model and the two dimensional isentropic model. The first row indicates the combustion temperature in kelvin and degrees f, the chamber pressure as specified, the total enthalpy of the mixture kcalsystem mass, total entropy of the system calksystem mass, cpcv, which is the ratio of specific heats, gas number of gas moles in the mixture, and rtv a conversion factor which is not normally used. Finished motors are usually xrayed to ensure that the propellant grain is homogeneous, bonded everywhere to the case, and free of cracks. The nozzle was the lworkingm component of the rocket in which hot exhaust gases were accelerated and directed to achieve performance requirements and. Motor case design considerations in 5 what we know. We propose that motors made from these propellants can be safe and reliable and would make an excellent.

Although primarily intended for designing motors using kndextrose or knsorbitol propellant, other propellants may be specified with user inputted propellant properties. A propellant or propellent is a chemical substance used in the production of energy or pressurized gas that is subsequently used to create movement of a fluid or to generate propulsion of a vehicle, projectile, or other object. Propep software pc version of the propellant evaluation program with a graphical user interface gui added to greatly simplify usage of the program. Inflight refueling accidents are unheard of in flight test. Propellant grain article about propellant grain by the free. Ignition of the fuel grain, regression of the fuel grain, and oxidizer to fuel ratio shift during use are some of the difficult factors to design for in hybrid engines. Quick recap 2 motor and propellant selection nontoxic nondetonable htpbapal composite. Solid rocket grain configuration variational design method. Propep software pc version of the propellant evaluation. Martin an allnew sounding rocket was designed at nasas marshall space flight center that featured an aft finocyl, aluminized solid propellant grain and silicafilled ethylenepropylenediene monomer sfepdm internal insulation. Could 3d printing be used to achieve perfect grain geometry.

Thus the optimization of a case design frequently entails tradeoffs between case design parameters and vehicle design. The grain, which is the propellant bulk, is developed when the requirements of the rocket are known. It is therefore needed to have a method that calculates a graingeometry based on the given performance requirements. For very complex profiles, especially for the structural analysis, the use of numerical models is required. Internal ballistics simulation of a solid propellant. Design and analysis of propellant grain configurations for determination of the grain geometry which is an important and critical step in the design of solid propellant rocket motors, because accurate calculation of grain geometrical properties plays a vital role in performance prediction. Rocket propulsion an overview sciencedirect topics. We have made this propellant grain, or its predecessor design, for many years, and look forward. The currently used software, gdp1, is able to calculate the performance and burn behavior in detail. For design purposes we want to find the relationship between these performance parameters and the geometry. Evaluation criteria are listed in the description above. The rocket motor with the cured propellant is then cooled, the mandrel removed, and any final trimming or machining operations done. The most effective of these design criteria is the geometry of the solid propellant grain.

This highly useful thermochemical software allows the user to evaluate the theoretical performance of a solid or liquid rocket propellant. The design application is a lowflying, close air support cas aircraft using a separate exhaust turbofan engine. Propellant constant that depends on initial grain temperature. Simpson, on the use of statistics in design and the implications for. Nazumuddin 2assistant professor 2head of the department, 3post graduate student, 3assistant professor dept. To show the damage field in solid propellants under an actual service condition, we build a scaled cylindrical grain with an outer diameter of 20 mm and an inner diameter of 5 mm. The nozzle was installed at the aft end of the aft segment, at the bottom of the rocket. Burnback analysis of 3d star grain solid propellant. Understanding of the way in which the fuel grain recedes is important for design of the combustion chamber, injector, and nozzle. Ae6504 propulsion ii, third year, department of aeronautical engineering, first and second units questions. Includes many grain types, such as bates, finocyl, and moonburner. For over 35 years sea has specialized in the development of design and analysis software for chemical propulsion devices.

In the design and development of solid propellant rocket motors, the use of numerical tools able to simulate, predict and reconstruct the behaviour of a given motor in all its operative conditions is particularly important in order to decrease. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Burnsim is a solid rocket steadystate internal ballistics simulation software package for the windows platform. The solid performance program, spp12 is the latest version of the jannaf standard for performance predictions of solid propellant rocket motors srms. A solid propellant must not only produce a desirable specific impulse, but it must also exhibit satisfactory mechanical properties to withstand ground handling and the flight environment. Grain design program pro free download and software. Design optimization of solid rocket motor grains for. Solid propellant grain design and burnback simulation using a minimum distance function article in journal of propulsion and power 232. An important physical property of the propellant grain is the mass density, which is used in performance calculations. Elastomeric thermal insulation design considerations in. Conceptual design and structural analysis of solid rocket. It was shown that there exists an optimal slope of the line zx providing maximum combustion efficiency for a given mass of metal in the propellant grain. Hybrid rocket fuel grain theory and design considerations.