POWER GENERATING SYSTEMS FOR MANNED SPACE VEHICLES

Investigation of an integrated hydrogen production system based on nuclear and renewable energy sources: Comparative evaluation of hydrogen production options with a regenerative fuel cell system

In space applications, one of the main issues is to obtain an efficient power supply. There are various types of energy sources to produce electrical power which is needed for the operation of all active spacecraft systems and subsystems. Due to the dependency of distance from the Sun, solar energy source has limited application area. On the other hand, nuclear energy sources are widely preferred to provide electrical power during many deep space and planetary science missions. Using the radioactive decay process or fission reactor, nuclear energy is converted to thermal energy. This thermal energy can be used directly for heating issues or converted to electrical energy. Thermal energy is converted to electrical energy by means of both static and dynamic thermo-electric conversion technologies. An overview of nuclear energy technologies and nuclear energy based power systems utilized in the deep space missions take place in this paper.

<div class="htmlview paragraph">In the past decade, the space shuttle has been the key factor for the United States manned space exploration. In fact the space shuttle is the only means in which the United States government can send humans into space. However, the space shuttle's life-expectancy is due to expire around the year 2005. In preparation for the end of the space shuttle era, we, as a country, must decide what type of future space vehicle is appropriate to accomplish our future national goals in space.</div> <div class="htmlview paragraph">There are many public policy alternatives to the question: ‘What will replace the space shuttle?’ First, the United States could try a conservative approach to space exploration by developing and using an unmanned vehicle. Second, the government could opt for utility by developing a mixed fleet of launch vehicles. Third, the United States could try to modify and update the current space shuttles with new technology. Fourth, the United States could choose to invest its money in more ‘exotic’ space vehicle programs such as the Single-Stage-To-Orbit(SSTO) space plane and the Two-Stage-To-Orbit(TSTO) space plane. Lastly, the United States could try to initiate talks with other countries concerning an international space agency that could pool the finances and resources into one unified space program.</div> <div class="htmlview paragraph">In my final recommendation, I would first look into a possible international cooperation for future funding and operation of space transportation. However, if this first objective is unable to produce any type of cooperation within a couple of years, I would initiate a parallel future space vehicle program that would involve most of the modification of the space shuttle option and all of the mixed fleet option. Along with these main public policy recommendations, I also recommend some administrative suggestions that could prove vital in trying to carry out the public policy of future space vehicles.</div>

<div class="section abstract"><div class="htmlview paragraph">THE problem of this study was: <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">Can a method of analysis be found which adequately predicts the heat-transfer and cyl-wall temperature phenomena in diesel engines?</div></li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">Are there criteria for the design of diesel engine cyl that give the limits of reliable practice as found in typical diesels?</div></li></ol></div><div class="htmlview paragraph">Such a method of analysis is detailed in this paper. Design criteria were also found which appear applicable to broad classes of diesel engines. It was determined that the method was useful in prediction of the thermodynamic performance of a diesel insofar as the influence of cyl heat transfer on efficiency, power, and cooling load were predictable.</div></div>

<div class="section abstract"><div class="htmlview paragraph">This paper will propose a novel power generating system concept including an auxiliary, backup and emergency power source. Existing aircraft employ an auxiliary power unit (APU) and a ram air turbine (RAT) for power generation besides aero-engine generators. An APU works prior to starting propulsion on the ground and as a backup power plant during flight. The RAT is activated due to the need to maintain the essential systems in the case of an emergency situation. Both systems are optimized on conventional aircraft in which hydraulic, pneumatic and electric systems are supplied for control and equipment.</div><div class="htmlview paragraph">Although a conventional aircraft needs hydro pumps and air compressors, the coming of a new era of more-electric architecture for aircraft and propulsion will be the stimulus to improve aircraft systems [<span class="xref">1</span>]. In more-electric aircraft, the authors focus on the low-pressure spool generation system of aero-engines. This system is anticipated for large power sources that supply electricity to a bleed-less system, though the high-pressure spool-generating capability is restricted because of the mechanical integrity of the power off-take and aero-engine control stability. LP generation contributes not only to the control stability for aero-engines but also to potential survivability of power generation since it is possible for LP spool to generate energy during wind milling.</div><div class="htmlview paragraph">This paper will discuss the overview of the more-electric aircraft utility resource. To introduce the substituting technology of a conventional power-generating system that relies on RAT and APU, the authors will propose a low-pressure spool-generating architecture involving any power management measures, upon the electrical power demand estimation.</div></div>

<div class="section abstract"><div class="htmlview paragraph">A significant step is achieved on the flight control actuation system toward the more electrical aircraft through the Airbus A380, A400M and the A350 development phase ongoing. The A380/A400M/A350 features a mixed flight control actuation power source distribution, associating electrically powered actuators with conventional FlyByWire hydraulic servocontrols.</div><div class="htmlview paragraph">In the scope of the preparation of the future Airbus Aircraft, this paper presents the perspectives of the use of the EMA technologies for the flight control systems in the more electrical aircraft highlighting the main technical challenges need to treat: jamming susceptibility, “on board” maintenance reduction, Operational reliability increase, power electronics and power management optimization, and regarding the environmental constraints, the predicted performances; the benefits associated to the optimized utilization of on-board power sources.</div><div class="htmlview paragraph">On the 4<sup>th</sup> of January 2011, an aileron EMA was successful flown on Airbus A320 MSN1. It is an important step towards the EMA technology for flight control actuation system.</div></div>

<div class="section abstract"><div class="htmlview paragraph">The attitude of autonomous marine, land, air or space vehicles can be determined from the state estimation by means of mathematical tools such as Extended Kalman filter. In the process of calculation of this value, three-axis inertial and non-inertial sensors are used. From the knowledge of the orientation of the main axis, it is implemented the automatic control of the vehicle.</div><div class="htmlview paragraph">The solid-state magnetometer is a non-inertial sensor with three axes that provides both the direction and the magnitude of the magnetic field vector which it is being submitted. However, measurements of the Earth's magnetic field vector, obtained using the three-axis magnetometer, are not accurate. In the vehicle itself, the presence of ferrous materials creates disturbances in the Earth's magnetic field, distorting the measured field. The accuracy of the magnetometer can be improved by means of various calibration methods, which, in summary, calculate the vector components of the bias, the systematic error, which can be modeled as a magnetic field that overlaps and distorts the actual terrestrial magnetic field. More than 90% of the measured geomagnetic field is generated in the earth's outer core and can be described by mathematical models that serve as reference to some of the magnetometer calibration algorithms.</div></div>

<div class="section abstract"><div class="htmlview paragraph">THIS paper discusses the modern concept of afterburner design, breaking down the various major components and treating, as fully as allowable under secrecy imposition, the problems confronting the design engineer.</div><div class="htmlview paragraph">Because an afterburner must provide short bursts of speed during take-off, climb, and combat maneuvering, without affecting the normal operation of the main turbojet engine, it is necessarily very complex. Essentially, it is a complete engine attached to the exhaust of the turbojet engine. By burning additional fuel in a specially designed tailpipe, the afterburner raises the temperature of the jet gases after they leave the turbine.</div><div class="htmlview paragraph">Early designs are evaluated, with advantages and disadvantages pointed out. Actuator power sources are dealt with and suggestions given for future development.</div><div class="htmlview paragraph">Comparisons are drawn between the nonafter-burning jet engine and that incorporating an afterburner.</div><div class="htmlview paragraph">Where secrecy imposition makes specific discussion impossible, a general introduction to the subject is attempted.</div></div>

<div class="htmlview paragraph">DLS offers exciting new possibilities for design and performance of headlamps. The powerful HID source technology is ideally suited to serve as light source for such a DLS, combining the benefits of both technologies to a completely new headlighting concept.</div> <div class="htmlview paragraph">The intention of the paper is to give an impression of the efficiency and performance of the system and to point out the prerequisites and parameters for the light source that influence the performance.</div> <div class="htmlview paragraph">Starting from the performance of present HID headlamps and based on sound considerations of losses of the various components of a DLS, the beam requirements are traced back to the necessary properties of a HID light source and bulb driver dedicated for DLS.</div> <div class="htmlview paragraph">From both calculations and measurements an estimation of the overall performance for the system is derived, with focus on incoupling efficiency.</div>

<div class="section abstract"> <div class="htmlview paragraph">Reference lines have been developed to which driver workspace accomodation tools can be located in vehicle space. The lines describe horizontal reference point locations as a function of vehicle H-point height (H30). One reference line has been established for use in vehicles with H-point heights (H 30) and steering wheel diameters (W9) less than 405mm and 450mm, respectively. (Class A Vehicles) This point can be used to reference appropriate workspace tools to accommodate a driver population with a male to female ratio of one to one. Separate reference lines have been established for use in vehicles with H-point heights (H30) between 405 and 530mm and steering wheel diameters (W9) between 450 and 560mm with treadle type pedals. (Class B Vehicles) See <span class="xref">Fig. 1</span>. Three lines are available for use in Class B vehicles depending on the percentages of males and females in the population the designer wishes to accommodate. Separate points can be used to reference appropriate workspace tools to accommodate driver populations with male/female ratios of 50/50, 75/25 and 90/10 to 95/5. Different procedures for locating Class A and Class B Accommodation Tool Reference Lines in vehicle space have been established based on unique packaging considerations of the two categories of vehicles.</div></div>

Technical analysis for optimum hydrogen production using nuclear–renewable hybrid energy system

<div class="htmlview paragraph">Control of sound levels in vehicles is becoming an integral part of the design criteria used by vehicle and equipment designers. Standards are in place which require noise control and the consumers are demanding the control for the safety and productivity of their workers.</div> <div class="htmlview paragraph">Molded fiber glass offers solutions to the noise control problems as well as providing many other product benefits. The fiber glass can be easily molded into parts of various shapes and densities that provide both acoustical and thermal control for the service life of the system.</div> <div class="htmlview paragraph">The fiber glass parts offer consistent performance with minimum variation from part to part. This effective and consistent performance allows a designer to be more confident that a given design will perform as intended.</div> <div class="htmlview paragraph">Molded fiber glass parts can be an extremely cost effective way for vehicle and equipment designers to address concerns with thermal and acoustical energy. With the emphasis on performance, reliability and comfort which exists in todays cost competitive business environment, designers have a monumental task to choose materials which can handle a variety of concerns at the lowest possible total installed cost.</div> <div class="htmlview paragraph">Fiber glass can be molded into many different shapes and densities. It can also be easily incorporated as part of a composite design to address specific physical property or aesthetic application requirements. When used as part of a well designed system, fiber glass can perform as intended for the full service life of the system.</div> <div class="htmlview paragraph">This paper will address some of the physical performance characteristics which make fiber glass molded parts an attractive choice for equipment and vehicle designers.</div>

<div class="htmlview paragraph"><b>I</b>T is common practice to provide single-filament motor-vehicle head-lamps with but one focus-adjusting mechanism. The advisability of incorporating also a vertical-focusing mechanism in two-filament tilting-beam head-lamps has been a subject of discussion.</div> <div class="htmlview paragraph">The intent of State laws is to require the proper use of lighting equipment that meets the legal requirements. Focusing is the most difficult obstacle in the way of practical enforcement of the laws. Types of focusing mechanism are described and the effect of the use of each type on the instructions issued by State motor-vehicle departments is explained at some length.</div> <div class="htmlview paragraph">Movement of the light source by the use of the different types of mechanism for focusing head-lamps is described to explain complications that attend the use of multiple adjusting-mechanisms. Head-lamps can be designed with a focal zone, instead of a focal point, so that they will be less sensitive to filament positioning. A sampling of bulbs in dealers' stocks shows that the variation in accuracy of commercial electric incandescent lamps is within the practical limits of compensated single-focus design.</div> <div class="htmlview paragraph">Comparison is made between the adjustment of head-lamps in service which have one focusing-mechanism and two focusing-mechanisms. The deterrent effect of multiple-adjustment mechanisms on future development is discussed.</div> <div class="htmlview paragraph">Proposals to rectify unsatisfactory night-driving conditions should be based upon the elimination of their primary causes. Various authorities agree with these views. The different uses of the vertical adjustment are considered.</div>

<div class="section abstract"> <div class="htmlview paragraph">A Driver Selected Seat Position tool has been developed to describe where certain percentages of drivers position horizontally adjustable seats in various workspace arrangements. The tool consists of series of equations that describe horizontal H-point locations as a function of vehicle H-point height (H30). One series of equations have been established for use in vehicles with H-point heights (H30) and steering wheel diameters (W9) less than 405 mm and 450 mm, respectively (Class A Vehicles). This class of vehicles includes passenger cars, vans and light trucks. The lines describe the 2.5th, 5th, 10th, 50th, 90th, 95th and 97.5th percentile accommodation levels expressed as H-point location for a driver population with a male to female ratio of one to one. Separate driver selected seat position equations have been established for use in vehicles with H-point heights (H30) between 405 and 530 mm and steering wheel diameters (W9) between 450 and 560 mm with treadle type pedals (Class B Vehicles). See <span class="xref">Fig. 1</span>. This class of vehicles includes heavy trucks and some buses and multipurpose passenger vehicles. Three series of equations are available for use in Class B vehicles depending on the percentages of males and females in the population the designer wishes to accommodate. Separate equations describe the accommodation level for driver populations with male/female ratios of 50/50, 75/25 and 90/10 to 95/5. Different references for locating Class A and Class B Driver Selected Seat Position Lines in vehicle space have been established based on unique packaging considerations of the two categories of vehicles. For both vehicle classes, the lines can be used as a design tool to estimate the location and length of horizontal seat travel aft of the appropriate reference to provide accommodation of target percentages of drivers. The lines can also be used as a checking tool to estimate the level of accommodation provided by a given horizontally adjustable seat track.</div></div>

<div class="htmlview paragraph">The use of pyrotechnic devices in missiles and space vehicles creates a hazardous environment for equipment. Several reported flight anomalies concurrent with the separation event prompted Lockheed Missiles & Space Co. to devote considerable effort to establish methods of treating pyrotechnic shock. An extensive ground testing program included activation of the vehicle’s pyrotechnic systems and subsequent measurement of the shock.</div> <div class="htmlview paragraph">Several methods of improving confidence in equipment performance during pyrotechnic shock by means of electrical modifications, shock mounting, and testing were investigated.</div> <div class="htmlview paragraph">In addition to treatment of present shock problems, a program was initiated to reduce the pyrotechnic shock levels in the vehicle by redesigning the booster separation joint. Several methods of achieving a qualification testing system for equipments is included in the discussion of the system and specification which LMSC presently uses.</div> <div class="htmlview paragraph">The present status of the shock problem with future proposed LMSC effort is also discussed.</div>