scholarly journals Discussion of the Fluid Acceleration Quality of a Ducted Propulsion System on the Propulsive Performance

2022 ◽  
Vol 130 (3) ◽  
pp. 1325-1348
Author(s):  
Jui-Hsiang Kao ◽  
Yi-Fan Liao
Keyword(s):  
Propulsion System ◽  
Propulsive Performance

scholarly journals Design and In-orbit Demonstration of REGULUS, an Iodine electric propulsion system

2021 ◽  
Author(s):  
Nicolas Bellomo ◽  
Mirko Magarotto ◽  
Marco Manente ◽  
Fabio Trezzolani ◽  
Riccardo Mantellato ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Specific Impulse ◽  
Input Power ◽  
Propulsion System ◽  
Electric Propulsion System ◽  
Propulsive Performance ◽  
Plasma Thruster ◽  
Total Impulse ◽  
Acceptance Tests

AbstractREGULUS is an Iodine-based electric propulsion system. It has been designed and manufactured at the Italian company Technology for Propulsion and Innovation SpA (T4i). REGULUS integrates the Magnetically Enhanced Plasma Thruster (MEPT) and its subsystems, namely electronics, fluidic, and thermo-structural in a volume of 1.5 U. The mass envelope is 2.5 kg, including propellant. REGULUS targets CubeSat platforms larger than 6 U and CubeSat carriers. A thrust T = 0.60 mN and a specific impulse Isp = 600 s are achieved with an input power of P = 50 W; the nominal total impulse is Itot = 3000 Ns. REGULUS has been integrated on-board of the UniSat-7 satellite and its In-orbit Demonstration (IoD) is currently ongoing. The principal topics addressed in this work are: (i) design of REGULUS, (ii) comparison of the propulsive performance obtained operating the MEPT with different propellants, namely Xenon and Iodine, (iii) qualification and acceptance tests, (iv) plume analysis, (v) the IoD.

Simulation of the Application of Pneumatic Propulsion Method in Tourist Submarine

2010 ◽  
Vol 43 ◽  
pp. 603-609
Author(s):  
Bin Cheng Li ◽  
Bing Han
Keyword(s):  
High Pressure ◽  
Thrust Force ◽  
Propulsion System ◽  
Air Motor ◽  
Oxygen System ◽  
Selection Of

In order to realize propulsion system and oxygen system of tourist submarines be secure, eco-friendly, efficient, reliable, economical, a combination of ordinary air motor and ACM high-pressure air bottle is adopted for providing propulsion and oxygen. The calculation and selection of the appropriate air motor and high-pressure bottle are based on the propulsive requirement of a tourist submarine. A model consists of high-pressure bottle, air motor, propeller and the resistance of the tourist submarine is established in SimulationX. The underwater speed and it’s duration are obtained through calculation as the rev, thrust force, torque of the propeller, etc. The possibility of application of pneumatic propulsion method in tourist submarine is analysed. Results illustrate that: on the premise of lightened quality of the propulsion system, pneumatic propulsion method fulfills the required underwater speed and it’s duration.

412 Propulsive Performance of Outboard Propulsion System Using Oscillating Dolphin-like Tail Fin for Propulsor

2008 ◽  
Vol 2008.45 (0) ◽  
pp. 127-128
Author(s):  
Tetsuya YOSHIIKE ◽  
Hirohisa MORIKAWA ◽  
Shunichi KOBAYASHI ◽  
Motomu NAKAZIMA
Keyword(s):  
Propulsion System ◽  
Propulsive Performance

The Establishment and Weight Calculation Method of Evaluation Indexes for the Float Board Propulsion System

2014 ◽  
Vol 597 ◽  
pp. 464-467
Author(s):  
Yao Quan Cai ◽  
Fan Ming Zeng ◽  
Jin Lin Liu
Keyword(s):  
Calculation Method ◽  
Evaluation System ◽  
Propulsion System ◽  
System Study ◽  
Analytic Hierarchy ◽  
Evaluation Indexes ◽  
Weight Calculation ◽  
Method Of Evaluation ◽  
Hierarchy Process

This article aims at solving the problem of evaluation indexes establishment in the process of complexity and the evaluation indexes weight calculation in the process of ambiguity and uncertainty for the float board propulsion system, study and establish evaluation system of the float board propulsion system, make an intensive analysis of calculation method for indexes weight based on rough analytic hierarchy process and calculate the weight of evaluation indexes for the float board propulsion system. This will provide scientific guidance for design and evaluation of the project and lays the certain theory foundation for quality of the design for the float board propulsion system.

Propulsive Performance of Ideal Detonation Turbine Based Combined Cycle Engine

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Hua Qiu ◽  
Cha Xiong ◽  
Chuan-jun Yan ◽  
Wei Fan
Keyword(s):  
Pressure Ratio ◽  
Area Ratio ◽  
Combined Cycle ◽  
Performance Model ◽  
Propulsion System ◽  
Pulse Detonation Engine ◽  
Inlet Temperature ◽  
Pulse Detonation ◽  
Propulsive Performance ◽  
Detonation Engine

A novel two-mode propulsion system based on detonation combustion, known as a detonation turbine based combined cycle engine (DTBCC), was proposed and thermodynamically analyzed for potential application to aircrafts whose flight Mach number is from 0 to 5. The obvious advantage of the two-mode system is that both modes share the same multidetonation chambers. The quasi-stable total temperature and total pressure for inlet conditions of the turbine could be realized in this hybrid pulse detonation engine. A key parameter (drive area ratio) was defined as the ratio of the outflow area at the head to the cross-sectional area of the detonation chamber. The calculated results showed that the increase of the drive area ratio led to the increase in the mass flow entering the turbine; however, this led to the decrease of the total inlet temperature, the total inlet pressure, and the expansion-pressure ratio of the turbine. Compared with an ideal turbojet engine, the inlet temperature of the turbine in a preturbine hybrid pulse detonation engine with a drive area ratio of 1 was 80 K lower than the former under the same pressure ratio and the same fuel-air ratio. In other words, the increase of the drive area ratio may improve the performance of this hybrid pulse detonation engine. Variation of the pressure ratio was adapted to varied flight Mach numbers by a change of the drive area ratio, which induced the enlargement of the operating range. Finally, a performance model was established to research the components’ characteristics and the propulsive performance of the engine. Preliminary performance estimates suggested that thrust and specific fuel consumption of the two-mode propulsion system were superior to the existing turbine based combined cycle designs.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

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