Designing of a combined propulsion system for the first stage of the rocket

2021 ◽  
pp. 69-75
Author(s):  
К.В. Щурин ◽  
С.А. Береснев ◽  
В.А. Капустин
Keyword(s):  
Environmental Factor ◽  
Propulsion System ◽  
Advantages And Disadvantages ◽  
Similar Development ◽  
Current Systems

Статья посвящена разработке комбинированной двигательной установки первой ступени ракеты. Рассмотрены действующие системы, их преимущества и недостатки, а также задача выведения большего количества полезной нагрузки в космос за счёт уменьшения веса топлива, а также улучшения экологического фактора. Показана аналогичная разработка КДУ. Представлены расчеты веса конструкции и количества топлива. The article is devoted to the development of the combined propulsion system of the first stage of the rocket. The current systems, their advantages and disadvantages, as well as the task of bringing more payload into space by reducing the weight of fuel, as well as improving the environmental factor are considered. A similar development of the CPS is shown. Calculations of the weight of the structure and the amount of fuel are presented.

scholarly journals Propulsion Systems in Marine Navigation

2018 ◽  
Vol 24 (3) ◽  
pp. 78-82 ◽  
Author(s):  
Gheorghe Samoilescu ◽  
Dumitru Iorgulescu ◽  
Robert Mitrea ◽  
Laura D. Cizer
Keyword(s):  
Research Study ◽  
Poor Performance ◽  
Propulsion System ◽  
Propulsion Systems ◽  
Cost Of Transport ◽  
Analysis And Design ◽  
Advantages And Disadvantages ◽  
The Cost ◽  
Marine Navigation ◽  
Main Factor

Abstract This paper presents variants of propulsion systems as the main factor in the analysis and design of the power system of a sea-going or river vessel; this topic is also under research study within two doctoral theses. The analysis of the ship - main propulsion- thruster assembly is made according to the requirements imposed by the market economy. The parameters to be considered when choosing a propulsion system are: the cost of the investment, the specific cost of transport that depends both on the specific fuel consumption and on the number and level of pay of the crew members operating the propulsion system, the propulsion efficiency, the high safety in handling, and the control accessibility during operation. The Pod and Azipod propulsion systems are analyzed in terms of advantages and disadvantages compared to conventional propulsion systems. The azimuth thrusters can ensure maximum push in any direction regardless the speed of the ship, and thus can change the course of the ship according to its handling needs. The azimuth thrusters do not only operate in horizontal but also in oblique angles, providing the ship with great maneuverability, even at low speeds, where classical rudder systems have poor performance

scholarly journals Methods for determining mechanical losses of marine diesel engines

2018 ◽  
Vol 214 (3) ◽  
pp. 25-38
Author(s):  
Leszek Wontka
Keyword(s):  
Diesel Engines ◽  
Critical Evaluation ◽  
Propulsion System ◽  
Piston Engine ◽  
Advantages And Disadvantages ◽  
Marine Propulsion ◽  
Marine Diesel ◽  
Marine Propulsion System

Abstract The paper presents based on literature critical evaluation of commonly known methods for determining the mechanical losses of a piston engine. Their advantages and disadvantages were pointed out also the possibility of their use in a marine propulsion system was assessed.

United Kingdom

2010 ◽  
pp. 192-213
Author(s):  
David R. Green
Keyword(s):  
United Kingdom ◽  
Information Systems ◽  
User Interface ◽  
Floppy Disk ◽  
Local Scale ◽  
Google Earth ◽  
Advantages And Disadvantages ◽  
The United Kingdom ◽  
The Uk ◽  
Current Systems

This chapter briefly examines the origins and evolution of electronic coastal and marine atlases, and online mapping and GIS in the United Kingdom (UK). Beginning with some early examples, such as the UK Digital Marine Atlas (UKDMAP), initially distributed on floppy disk (MS-DOS) and later CD (MS-Windows), consideration is then given to some of the first online Internet-based information systems e.g., The UK Coastal Map Creator, some of the current systems now available e.g., MAGIC, MESH, and UKSeaMap, and finally the potential of Google Earth (GE) and Google Ocean (GO) to provide a framework for the development of simple local scale coastal and marine atlases. In each case, attention is paid to the origins of the atlas, its development, the user-interface, functionality, data and information content, and the target audience. Some of the advantages and disadvantages of electronic atlases are also discussed, together with some of the problems, and possible solutions.

Turboelectric Distributed Propulsion System As a Future Replacement for Turbofan Engines

2017 ◽  
Author(s):  
Borys Łukasik
Keyword(s):  
Technological Development ◽  
Thermodynamic Cycle ◽  
Practical Method ◽  
Propulsion System ◽  
Propulsive Efficiency ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Advantages And Disadvantages ◽  
Distributed Propulsion ◽  
Extra Weight

The main purpose of this paper is to discuss the possibility of standard turbofan engine replacement by the turboelectric distributed propulsion system, in future commercial aviation. Paper describes how the distributed propulsion allows to reach significantly greater propulsive efficiency than state-of-the-art high bypass turbofan engines, and presents turboelectric system as the only practical method of distributed propulsion implementation. However, since extra weight of the electric components that would be added can overcome the high propulsive efficiency benefit, a detailed analysis is needed to verify the feasibility of such system. This article shows results of such analysis that was conducted for 90 PAX class regional jet. Thermodynamic cycle calculations, performed for both, turbofan engine and turboelectric distributed propulsion are presented. They prove that distributed propulsion is able to provide great reduction in fuel consumption of uninstalled propulsion system, while performed mission analysis depicts the penalty of extra mass of electric appliances, showing actual profits that are achievable. On this example, advantages and disadvantages of the turboelectric distributed propulsion system in comparison with modern turbofan engines are discuss, taking into account the potential technological development of turbofan engine and additional non-propulsive benefits that turboelectric system is able to provide. Finally, this document also presents mass estimations for different scenarios of electric appliances evolution, which highlight the technology levels that need to be achieved before the system can be introduced in commercial service.

An Estimation Method for the Torsional Vibration of the Marine Propulsion System

2015 ◽  
Vol 220-221 ◽  
pp. 71-80 ◽  
Author(s):  
Lech Murawski ◽  
Adam Charchalis
Keyword(s):  
Power Transmission ◽  
Estimation Method ◽  
Transmission System ◽  
Propulsion System ◽  
Torsional Vibrations ◽  
Shaft Line ◽  
Advantages And Disadvantages ◽  
Power Transmission System ◽  
Marine Propulsion ◽  
Marine Propulsion System

The paper presents an estimation analysis methopd for the natural mode and frequency of the torsional vibrations of a marine power transmission system. A typical merchantman marine propulsion system is made up of a slow speed main engine connected to a directly driven propeller by a relatively short shaft line. Although all classification societies require calculating the operating parameters of the propulsion system, however, they have no simplified formulas. The torsional vibrations of the marine power transmission system are usually the most dangerous for the shaft line and crankshaft. Numerical algorithms based mostly on the Finite Element Method (FEM) are unobtainable and not useful for a ship crew. The chief of marine engineers should have checked a possibility of the analysis and measurements of torsional vibrations. The authors have investigated an estimation method of the torsional vibrations of the system. The article deals with a simulation method for more difficult parameters of the propulsion system like propeller water added mass moment of inertia. The paper also briefly describes the advantages and disadvantages of the undercritical and overcritical propulsion system and discusses calculation results included in the final part of the work. The introduced calculation method has been verified comparing detailed FEM estimations and the measurements of real ships.

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.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

A conduction-cooled stage for high-resolution Cryo-SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1282-1283
Author(s):  
John G. Sheehan
Keyword(s):  
High Resolution ◽  
Liquid Nitrogen ◽  
Mechanical Stability ◽  
Cooling System ◽  
Cold Trap ◽  
Nitrogen Gas ◽  
Particulate Suspensions ◽  
Advantages And Disadvantages ◽  
Convection Cooling ◽  
Styrene Butadiene

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.

Computer simulations for the TEM bend contour technique

1996 ◽  
Vol 54 ◽  
pp. 134-135
Author(s):  
Vladimir Yu. Kolosov ◽  
Anders R. Thölén
Keyword(s):  
Computer Simulations ◽  
Real Space ◽  
Advantages And Disadvantages ◽  
Short Overview ◽  
Diffraction Contrast ◽  
Beam Method ◽  
Convergent Beam ◽  
Contour Technique

In this paper we give a short overview of two TEM applications utilizing the extinction bend contour technique (BC) giving the advantages and disadvantages; especially we consider two areas in which the BC technique remains unique. Special attention is given to an approach including computer simulations of TEM micrographs.BC patterns are often observed in TEM studies but are rarely exploited in a serious way. However, this type of diffraction contrast was one of the first to be used for analysis of imperfections in crystalline foils, but since then only some groups have utilized the BC technique. The most extensive studies were performed by Steeds, Eades and colleagues. They were the first to demonstrate the unique possibilities of the BC method and named it real space crystallography, which developed later into the somewhat similar but more powerful convergent beam method. Maybe, due to the difficulties in analysis, BCs have seldom been used in TEM, and then mainly to visualize different imperfections and transformations.

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