c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization.

A01-34382

AIAA 2001-3704

EXPERIMENTAL INVESTIGATION ON AEROSPIKE

NOZZLE IN DIFFERENT STRUCTURES AND

WORKING CONDITIONS

Liu Yu, Zhang Guozhou, Dai Wuye, Ma Bin,

Cheng Xianchen, Wang Yibai, Qin Lizi

Wang Changhui, Li Junwei

Beijing University of Aeronautics and Astronautics

Beijing,PRC, 100083

37th AIAA/ASME/SAE/ASEE Joint Propulsion

Conference and Exhibit8-11 July 2001

Salt Palace, Salt Lake City, UTFor permission to copy or to republish, contact the copyright owner named on the first page.

For AIAA-held copyright, write to AIAA Permissions Department,1801 Alexander Bell Drive, Suite 500, Reston VA, 20191-4344.

c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization.

AIAA 2001-3704

EXPERIMENTAL INVESTIGATION ON AEROSPIKE NOZZLE IN DIFFERENTSTRUCTURES AND WORKING CONDITIONS

Liu Yu* Zhang Guozhou* Dai Wuyef Ma Bin* Cheng Xianchen* Wang Yibaif

Qin Lizi Wang Changhui Li Junwei1^

Beijing University of Aeronautics and Astronautics, Beijing, 100083, PRC.

AbstractFor an approximate design of aerospike nozzle,

some numerical and experimental studies andconclusions are given here. The numericalsimulations contain of both the Method ofCharacteristic and the solving of the Navier-Stokesequations. The experimental system and severalkinds of the test aerospike nozzle are showed here.Some tests and calculations curves are presented andexplained.

IntroductionAerospike nozzle is much complicated in

structure than that of the bell nozzle, so the optimizedstructural design of an aerospike nozzle has morequestions need to be answered in ahead. For example,what's the best inclination angle of the side nozzlecell? How much effect to the nozzle performance thatthe plug base will cause when the supersonic gasflow around the base is closed or unclosed? Thestudy conducted here is trying to answer questionslike these.

Experimental SystemThe schematic diagram of the experimental

system is showed in Figure 1. The system mainlyincludes the gaseous Oxygen supply system, thepressurized feed system of the fuel ethyl alcohol, thepressurized water circulating cooling system, thehigh-pressure air source, the vacuum pump and twolarge cylindrical vacuum exhaust tanks, the amplifier

* Professor, School of Astronautics, BUAAf PH.D. Student, School of Astronautics, BUAA* Engineer, School of Astronautics, BUAACopyright © 2001 by the American Institute of Aeronauticsand Astronautics Inc. All right reserved.

and computer data acquisition system, manualcontrolling and monitoring system, the cubic testvacuum room and the test aerospike engine inside it.

The measuring parameters are mainly composedof two chamber pressures, chamber temperature, 2-4oxygen head pressures, 2-4 fuel head pressures,chamber pressure and temperature of the igniter,head oxygen and fuel pressures of the igniter, massflow rates of oxygen and fuel.

Test Aerospike NozzleAfter thousands of optimized performance

computations have been done by using Method ofCharacteristic, several kinds of aerospike nozzleconfigurations have been formed. The configurationscomposed of bell side nozzle circular-linearcomposite structure with curved plug contour shownin Figure 2 and Figure 3, rectangular throat linearaerospike nozzle with different side nozzle angles(Fig. 4) and water cooled square shape linearaerospike nozzle (Fig. 5). Most of them will be usedto do the experiments to confirm the effectiveness ofthe design.

The model in figure 2 is a practical useful modelsuggested by us. The benefit of it is that theconventional axisymmetrical thrust chamber can beused with little change, and that the base is alwaysclosed both on ground and in a certain flight altitude.

The model in figure 3 is a simplified one byusing of 14 conical nozzles, 4 thrust chamber headsand one common chamber. The base mass flow ratepercent can be adjusted according needs. This modelwas designed specially to test the optimized basemass flow rate.

The model in figure 4 is a two-cell aerospike

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c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization.

nozzle and is specially used to test the bestinclination angle of the primary nozzle or sidenozzle.

The model in figure 5 is a four-unit aerospikenozzle. Two of them are made up of 5 thrust chamberunits, and the others are formed by 2 units. Each unitwill be cooled by water so that the model can work ina higher temperature and longer time. It wasspecially designed to test the effects with or withoutbase closing.

Test ResultsFrom the tests, some important parameters such

as thrust, chamber pressures are measured. Someother interested parameters such as nozzle efficiency,mass flow rate can be calculated by the measureddata. Briefly speaking, the results will mainlycontained of the multi-tube ignition properties to 14separated thrust chamber cells, the altitudeperformance compensating property and itscomparison for different nozzle structures, theperformance contribution by the plug base and so on.Figure 6 shows the test results of multi-tube ignition.Figure 7 gives the ignition property of the test modelin Figure 4. Figure 8 presents the working proceduresof the same model.

In figure 6, Tj, Pi? P0head and Tc represent thetemperature and pressure inside the chamber of theigniter, pressure of the oxygen head position and thetemperature at the exit position of several ignitertubes, respectively.

Figure 7 still shows the working procedure ofthe igniter, but it is a procedure accompanying theworking procedure of the aerospike engine. HerePfhead is the fuel head pressure. Figure 8 shows theresults of aerospike engine (model in figure 4) of thesame test as shown in figure 7. Here F, Pc, PCOhead>Pcftead and Tc represent the thrust, common chamberpressure, one oxygen and one fuel head pressure ofthe engine, and the common chamber temperature.

Numerical simulationsFigure 9 shows the optimized results by using

Method of Characteristics (MOC). The given

conditions are chamber pressure pc =3.0MPa,stagnation temperature T* =3260K, expansion ratioof the primary nozzle 8j =1. From this figure we cansee that the best primary nozzle inclination angle 8 isnearly equal to 30 at different backpressure or height.Figure 10 gives the similar results by solving theNavier-Stocks (NS) equations.

Figure 11 given the computed results of thecooling at the primary nozzle throat cross section.The calculation conditions are pc =3.0MPa, T*=3260K, the inner wall thickness 8=1.2/ww, thewidth and deepness of the tunnel 1.7X 1.2. Here, Twg,Twi, Twaterin and Twaterout represent the gaseous sidewalltemperature, the liquid sidewall temperature, thewater inlet and outlet temperature, respectively.

ConclusionsFor the test research are still undergoing, the

complete conclusions can't be given now, except thatthe best inclination angle of the primary nozzle isprobably about 30°. Another conclusion is that theangle will be affected strongly by other parameters m.The thrusts of the aerospike nozzle is a function ofpc,Sj, 0, pa, total expansion ration et and the base massflow rate. This will be also shown later.

Reference[1] Dai Wuye, Liu Yu, Zhang Zhengke, Qin Lizi,

Wang Yibai, "Numerical investigation on LinearAerospike Nozzles," Prepared for 37th

AIAA/ASME/SAE/ASEE Joint PropulsionConference and Exhibit, AIAA2001-3568, SaltPalace, Salt Lake City, UT, 8-11 July, 2001.

America Institute of Aeronautics and Astronautics

c)2001 American Institute of Aeronautics & Astronautics or Published w

ith Permission of Author(s) and/or Author(s)' Sponsoring O

rganization.

Am

erica Institute of Aeronautics and A

stronautics

c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization.

Figure 2. Circyiar-Mnear composite aerospike oozzle model.

Figure 3 Circular-linear composite aerospike nozzles without cooling

Figure 4 Rectangular throat linear aerospike nozzles with changeable side nozzle angle

Figure 5 Water-cooled square shape linear aerospike nozzles

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c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization.

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