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Thrust measurement experiment was carried out using a four-cylinder pulse detonation rocket engine (PDRE) with a rotary valve. The PDRE uses three types of gases, oxidizer, fuel, and purge gas to generate detonation wave intermittently and produces thrust. A rotary valve attached coaxially to a motor for supplying these three gases intermittently was used. The mechanism of the rotary valve is very simple. It is built up with a top cover, a rotating disk, and a casing, and has advantage to enable high mass flow rate and high frequency operation. In this study, pulse detonation rocket (PDR) for flight tests was developed. Thrust measurement experiment by grand test was carried out to check the performance of the this PDR. The oxidizer was N 2 O, the fuel was C 2 H 4 , and the purge gas was He. In the operation time for 1500 msec with C 2 H 4 -N 2 O propellant, we achieved time-averaged thrust of 256 N and specific impulse of 130.8 sec. Nomenclaturef D = detonation generating frequency f exp = experimental operation frequency f M = motor operation frequency f PDE = 1 PDE cycle frequency per tube I sp = propellant-based experimental specific impulse m i = purge gas mass flow rate m p = propellant mass flow rate P exp = oxidizer exhaust pressure (pressure between rotary valve and detonation tube) p i = purge gas supply pressure p p = propellant supply pressure R = gas constant T = temperature t ope = operation time V = volume  = equivalent ratio  p = propellant fill fraction

Thrust measurement experiment was carried out using a four-cylinder pulse detonation rocket engine (PDRE) with a rotary valve. The PDRE uses three types of gases, oxidizer, fuel, and purge gas to generate detonation wave intermittently and produces thrust. We used a rotary valve attached coaxially to a motor for supplying these three gases intermittently. The mechanism of the rotary valve is very simple. It is built up with a top cover, a rotating disk, and a casing, and has advantage to enable high mass flow rate and high frequency operation. The oxidizer was N 2 O, the fuel was ethylene, and the purge gas was He. In the operation time for 1000 msec with C 2 H 4 -N 2 O propellant, we achieved time-averaged thrust of 258.5 N and specific impulse of 138.7 sec. Nomenclature f M = motor operation frequency f PDE = 1 PDE cycle frequency per tube f D = detonation generating frequency f exp = experimental operation frequency I sp = propellant-based experimental specific impulse m i = purge gas mass flow rate m p = propellant mass flow rate p s,i = purge gas supply pressure p s,p = propellant supply pressure t ope = operation time  = equivalent ratio  p = propellant fill fraction  p,i = propellant and purge gas fill fraction  = rotation angle of rotating disc Subscripts i = purge gas p = propellant s = supply

A pulse detonation engine (Pulse Detonation Engine, PDE) generates a detonation wave intermittently, and obtains a thrust and work. In this research, the four cylinder pulse detonation rocket engine system "Todoroki II" was developed. The total weight of the flight test demonstrator is 32.5 kg. Moreover, the length is 1910 mm and the diameter of a combustion tube of a pipe in 800 mm is 37 mm. The launch and the recovery system for a flight test were also developed. The flight vehicle is recoveried without damage by winding system. It was proved that the flight test can be done repeatedly. In this flight test, the propellant mass flow estimated is m p =229 g/s. A time average thrust is F ave =254 N, the specific impulse of a propellant base is estimated to be I sp, PF =113 s, this specific impulse is 86 % of a ground test. The attitude of Todoroki incline to the positive direction of pitch up. The some factors of the inclination of Todoroki II are that the number of iginition different in each combustion tube and the attitude of Todoroki II launched is tilted. Considering these factors calculation results agree with experimental results in the attitude of Todoroki II. Nomenclature Isp,PF = experimental propellant-based specific impulse mp = propellant mas flow Fave = time-averaged thrust x = x position of center of gravity in launch-fixed coordinate y = y position of center of gravity in launch-fixed coordinate z = z position of center of gravity in launch-fixed coordinate N = number of ignition during 25 ms xl = x in launch-fixed coordinate yl = y in launch-fixed coordinate zl = z in launch-fixed coordinate xb = x in body-fixed coordinate yb = y in body-fixed coordinate zb = z in body-fixed coordinate Downloaded by KUNGLIGA TEKNISKA HOGSKOLEN KTH on August 11, 2015 | http://arc.aiaa.org |