A simplified design and optimization method of aerospike nozzle contour and the results of tests and numerical simulation of aerospike nozzles are presented. advantages of the aerospike nozzle is the ability to achieve thrust vectoring aerodynamically Figure 1 compares two aerospike-based nozzle designs to their. design strategy. Introduction. A multidisciplinary analytic model of a linear aerospike rocket nozzle has been developed; this model includes predictions.
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Salas and Herbert Dunn and Natalia M. Strictly speaking a minimum length nozzle requires a sharp corner at the throat. DalleJames F. Ratio of thruster internal exit area Desing to thruster throat area At.
The engine has a bell-shaped nozzle that has been cut in half, then stretched to form a ring with the half-nozzle now forming the profile of a plug. As a by product of the oblique shock wave analysis AeroSpike determines the shock wave angle for overexpanded flow and plots both the outer boundary contour and the initial shock wave from the lip of the cowl. Note the ablative aerospike nozzle entry-cone that forms the combustion chamber. However, no such engine is in commercial production, although some large-scale aerospikes are in testing phases.
Liquid Fuel Propellant Gases. Two wall-points, one from the center and one at the end of the nozzle contour have been selected for comparison.
For the example presented in Figure 2 and Figure 3, where the exit Mach number is 2. This page was last edited on 5 Novemberat KorteFarrokh Mistree It uses carbon composite materials and uses the same basic design for both stages.
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The terminology in the literature surrounding this subject is somewhat confused—the term aerospike was originally used for a truncated plug nozzle with a very rough conical taper and some gas injection, forming an “air spike” to help make up for the absence of the plug tail. Ratio of the chamber pressure Pc to the atmospheric pressure Pa.
Specify whether the nozzle is 2-D or 3-D by clicking either the 2-D characteristics or 3-D approximation option buttons. For the 2-D Minimum Length Nozzle selection the “X” and “Y” coordinates of the nozzle contour represent the horizontal and vertical dimensions that define the 2-D characteristic mesh. In JuneARCA announced that they would fly their Demonstrator3 rocket to space, using a linear aerospike engine. For pressure ratio, Pc is the thruster chamber pressure and Pa is the local atmospheric pressure.
In theory this requires an infinitely long spike for best efficiency, but by blowing a small amount of gas out of the center of a shorter truncated spike like base bleed in an artillery shellsomething similar can be achieved. The value for the ratio of specific heats g are determined from the Units and Gases menus and are passed on to the MLN program after clicking the Minimum Length Nozzle command button on the main start-up screen.
The Mach number at the exit of the nozzle where the flow is uniform. Input data for the results in Figure based on data from Figure-9 using AeroSpike version 2. Aerospike Engine Results Compared. In the toroidal aerospike the spike is bowl-shaped with the exhaust exiting in a ring around the outer rim. Requires QuickTime from Apple. Ratio of specific heats g: As the vehicle climbs to higher altitudes, the air pressure holding the exhaust against the spike decreases, as does the drag in front of the vehicle.
A minimum length nozzle has the smallest possible throat-to-exit length that is still capable of maintaining uniform supersonic flow at the exit. This effectively behaves like an “altitude compensator” in that the size of the bell automatically compensates as air pressure falls.
Multidisciplinary Approach to Aerospike Nozzle Design – Semantic Scholar
All important flow properties are displayed in real time as the locator moves from point to point in the flow field described by the characteristic mesh of the aerospike. The exhaust, a high-temperature mix of gases, has an effectively random momentum distribution i.
Radius that defines the projected area of the aerospike nozzle Re. For a nearly minimum length nozzle simply specify the streamline from the throat-curve so the curvature lines up with the nozzle wall shape generated by MLN. Since the pressure in front of the vehicle is ambient, this means that the exhaust at the base of the spike nearly balances out with the drag experienced by the vehicle.
Added a hybrid rocket motor propellant having the following fuel and oxidizer to the list of combustion gases: Inclination angle from sonic line: Rocketdyne conducted a lengthy series of tests in the s on various designs.
Selected from pull-down menu or user-defined. Define the analysis for annular 3-D or linear 2-D aerospike nozzles. Aerospike engines have been studied for a number of years and are the baseline engines for many single-stage-to-orbit SSTO designs and were also a strong contender for the Space Shuttle main engine. In the linear aerospike the spike consists of a tapered wedge-shaped plate, with exhaust exiting on either side at the “thick” end.
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Alexandrov Published A model of a linear aerospike rocket nozzle that consists of coupled aerodynamic and structural analyses has been developed. For a minimum length nozzle the maximum expansion angle is equal to one-half the Prandtl-Meyer function for the design exit Mach number. Aerospike nozzle total thrust is computed using the following equations knowing PR and percent truncation. Dimensional data for this analysis are based on Boeing’s results for the XRS linear aerospike rocket engine where vacuum thrust and Isp arelbf and Each time the user changes any data entry the results are automatically updated and displayed.
MunakataShigeru Sato This article has multiple issues. When placing this tag, consider associating this request with a WikiProject. Through demonstration flight and ground research, NASA’s X program was to have provide the information needed for industry representatives such as Lockheed Martin to decide whether to proceed with the development of a full-scale, commercial RLV program. For maximum accuracy simply insert 0. Please help to improve this article by introducing more precise citations.
The purpose of any engine bell is to direct the exhaust of a rocket engine in one direction, generating thrust in the opposite direction. For a detailed discussion of the method of characteristics please refer to the reference, Modern Compressible Flow, With Historical Perspective, by John D.