Keisuké Goto

Geometric throats are commonly applied to rocket combustors to increase pressure and specific impulse. This paper presents the results from thrust measurements of an ethylene/gas-oxygen rotating detonation engine with various throat geometries in a vacuum chamber to simulate varied backpressure conditions in a range of 1.1–104 kPa. For the throatless case, the detonation channel area was regarded to be equivalent the throat area, and three throat-contraction ratios were tested: 1, 2.5, and 8. Re

To create a new flyable detonation propulsion system, a detonation engine system (DES) that can be stowed in sounding rocket S-520-31 has been developed. This paper focused on the first flight demonstration in the space environment of a DES-integrated rotating detonation engine (RDE) using S-520-31. The flight result was compared with ground-test data to validate its performance. In the flight experiment, the stable combustion of the annulus RDE with a plug-shaped inner nozzle was observed by on

Recently, there has been increasing interest in Mobile Wireless Sensor Networks (MWSNs) that are constructed by mobile sensor nodes held by ordinary people, and it has led to a new concept called urban sensing. In such MWSNs, mobile sensor nodes densely exist, and thus, there are basically many sensor nodes that can sense a geographical point in the entire sensing area. To reduce the communication cost for gathering sensor data, it is desirable to gather the sensor data from the minimum number o

Recently, there has been increasing interest in Mobile Wireless Sensor Networks (MWSNs) that are constructed by mobile sensor nodes held by ordinary people, and it has led to a new concept called urban sensing. In such MWSNs, mobile sensor nodes densely exist, and thus, there are basically many sensor nodes that can sense a geographical point in the entire sensing area. To reduce the communication cost for gathering sensor data, it is desirable to gather the sensor data from the minimum number o

This Paper presents the results of a rotating detonation engine rocket sled test demonstration on a 127 mm gauge rail at 100 m long high-speed running track test equipment to evaluate the thrust performance of a stand-alone rotating detonation engine propulsion system. The developed sled test demonstrator contained all onboard subsystems, including engine, gas cylinders, valves, controller, and a data logger. The sled test demonstrator successfully generated thrust, and three or four detonation

A cylindrical rotating detonation engine (24 mm diameter) with multiple injector holes on the combustor side wall for both propellant injection and cooling by injector gas flow was designed and tested. As each set of injectors created its own detonations, the synchronized detonation waves propagated along the three injector rows. From the axial view, those detonation combustion regions stood off from the injector surface as the non-well-mixed propellant existed between the wall and the combustio

A method has been developed to detect the fine structures which appear in the total secondary electron yield σ and the back-scattering coefficient η as a function of primary electron energy Ep. The method is based on differentiating the σ-vs-Ep or η-vs-Ep curves by Ep by superimposing a small modulating voltage on Ep. To automatically record the σ- (or η-) vs-Ep and dσ/dEp- (or dη/dEp-) vs-Ep curves, the primary electron current was stabilized within ± 0.1% by regulating the temperature of the c

View Video Presentation: https://doi.org/10.2514/6.2022-0232.vid To create a new flyable propulsion system, Detonation Engine System (DES) has developed which can be stowed in the sounding rocket S-520-31. This paper focused on the first flight demonstration of RDE in space environment, which is integrated into DES, using S-520-31. The flight result was compared with the ground test data to validate its performance. In the flight experiment, the stable combustion of the RDE with aerospike nozzle

Secondary electron emission (SEE) properties of DC-705 (Trade mark: Dow Corning Chemical Co.), which is a molecular substance, have been studied. Measurements were made on SEE coefficient and on in elastic reflection coefficient for primary energy E p of 50–2000 eV at various thicknesses of DC-705 on a tungsten substrate. The maximum emission depth of inelastically reflected primaries is given as a function of E p and is proportional to E p n ( n =2.1±0.3). The maximum emission depth of true sec

A compact energy analyzer which has the four-grid construction as is widely used in LEED—Auger systems was developed to analyze secondary electrons. It is about 4.0 cm diam ×3.5 cm in length, with an entrance aperture of 5.6 mm diam and an angular aperture of about 10°. To get a uniform retarding field, a pair of fringing rings were added at the edge of the first and the second grids. The first and the second grids (gold coated tungsten, 100 mesh) were shaped into a portion of a sphere. The dist

Secondary electron and Auger electron spectra for two types of carbons, graphite and soot (glassy), have been measured in an absolute manner with a novel cylindrical mirror analyzer for primary energies 1 eV through 5 keV. The Auger electron, elastically backscattered primary, energy-loss, secondary-electron, and background signals have been related. The degree of crystallization modifies the characteristics of the secondary and energy-loss spectra drastically, though the background continuum wa

A designing and the construction of high speed pico-ammeter (HSPA) with feedback resistors (Rf) of 1011 and 1012Ω is described. The floating capacitance at the input and the distributed capacitance around the Rfcould be effectively compensated by using a guard method and compensating metal plates (4 pieces), respectively. The metal plates method is also capable of compensation for the non-uniformly distributed resistance of the Rf. Electronical circuits to reduce the Miller integration effect an