scholarly journals PRELIMINARY ANALYSIS OF SUPERCHARGED NUCLEAR RAMJET PROPULSION SYSTEM

1957 ◽  
Author(s):  
J A Boppart
Keyword(s):  
Preliminary Analysis ◽  
Propulsion System

Characteristics of gas-driven fan propulsion system for fixed-wing vertical take-off and landing aircraft

2021 ◽  
pp. 095441002110251
Author(s):  
Yang Zhou ◽  
Guoping Huang ◽  
Chen Xia ◽  
Yuanzhao Zhu
Keyword(s):  
Preliminary Analysis ◽  
Weight Ratio ◽  
Propulsion System ◽  
Development Cost ◽  
Ratio Requirement ◽  
Guide Vanes ◽  
The Core ◽  
Ducted Fan ◽  
Vtol Aircraft ◽  
Operation Characteristics

As a propulsion system for vertical take-off and landing (VTOL) aircraft, the gas-driven fan propulsion system has received some attention in recent years due to its simple mechanical structure and good performance. During the operation of the propulsion system, the core turbofan exhaust is directed to the tip turbine to drive the ducted fan to obtain thrust, and the louvered vector exhaust device is used to achieve lift/thrust switching. However, due to the linkage characteristics of the guide vanes of the exhaust device, the exhaust area will gradually change with the deflection of the guide vanes. This may cause uncertain effects on the system. Besides, considering the development cost of the propulsion system, it is necessary to clarify whether the core turbofan needs to be redesigned based on the characteristics of the system. Further, the transitional performance (VTOL to flight) of the propulsion system also needs to be studied. To this end, this study established an overall model of the gas-driven fan propulsion system combined with the characteristics of the core turbofan to analyze these problems. The results indicate that the louvered vector exhaust device can well match the gas-driven fan propulsion system. And when the propulsion system is composed, the gas-driven fan will not significantly affect the operation characteristics of the core turbofan. Besides, the preliminary analysis shows that the gas-driven fan propulsion system can meet the power requirements of the transition state of the fixed-wing VTOL aircraft. And the characteristics of the propulsion system may make the take-off thrust-weight ratio requirement of the fixed-wing VTOL aircraft be as low as 1.1.

FeXIV Line Emission Polarization of the July 11, 1991 Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 541-547
Author(s):  
J. Sýkora ◽  
J. Rybák ◽  
P. Ambrož
Keyword(s):  
High Resolution ◽  
Solar Corona ◽  
Emission Line ◽  
Solar Eclipse ◽  
White Light ◽  
Preliminary Analysis ◽  
Line Emission ◽  
Total Solar Eclipse ◽  
Degree Of Polarization ◽  
High Resolution Images

AbstractHigh resolution images, obtained during July 11, 1991 total solar eclipse, allowed us to estimate the degree of solar corona polarization in the light of FeXIV 530.3 nm emission line and in the white light, as well. Very preliminary analysis reveals remarkable differences in the degree of polarization for both sets of data, particularly as for level of polarization and its distribution around the Sun’s limb.

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.

AAC Supports for Individuals With Rett Syndrome Across the Lifespan

2015 ◽  
Vol 24 (3) ◽  
pp. 74-85
Author(s):  
Sandra M. Grether
Keyword(s):  
Rett Syndrome ◽  
Communication Skills ◽  
Preliminary Analysis ◽  
Multidisciplinary Approach ◽  
Motor Deficits ◽  
Complex Profile ◽  
Communication Behaviors ◽  
The Individual

Individuals with Rett syndrome (RS) present with a complex profile. They benefit from a multidisciplinary approach for diagnosis, treatment, and follow-up. In our clinic, the Communication Matrix © (Rowland, 1990/1996/2004) is used to collect data about the communication skills and modalities used by those with RS across the lifespan. Preliminary analysis of this data supports the expected changes in communication behaviors as the individual with RS ages and motor deficits have a greater impact.

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