High-speed Airplanes Research Articles

The promotion / demotion algorithm of moving objects with large velocity differences in time-parameterized spatio-temporal index

Overlapping costs increase due to a difference in speed of moving objects, ranging from low-speed submarines to high-speed airplanes in the time-parameterized spatio-temporal index. This paper proposes a new method for promoting fast moving objects to upper non-leaf nodes to minimize overlap when the speed difference between objects in the index is considerably large. Experimental evaluation on datasets of moving objects with large speed differences demonstrates that the performance of insertion and deletion is improved. Our results show that the performance of the prediction query with speed parameters is improved by 75.8% as compared to previous approaches.

Experimental analysis of shock stand-off distance over spherical bodies in high-enthalpy flows

The shock stand-off distance for basic spherical models was investigated in the flow regime of 1–2 km/s, a range for which data are unavailable in the open literature. Experiments were conducted on two hypersonic shock tunnels, at five different enthalpy conditions and two types of test gas, and the bow shock was captured using schlieren flow visualization technique. These results were compared with existing empirical relations and a good match was observed. To further corroborate the results, a computational analysis of the same problem was carried out using an in-house computational fluid dynamics code, HiFUN (High Resolution Flow Solver on UNstructured meshes), and the results were again seen to match well with the experiments. The shock stand-off distance is an important parameter for the design of high-speed airplanes, and therefore a solid quantitative understanding of this parameter is vital for all flow regimes. This paper aims to fill in the gap by investigating one of those regimes where available data are currently missing.

Problem of Multiparametric Optimization of the Construction of the Joint Between the Ceramic Hull and Metallic Fuselage of an Airplane

An approach to the solution of the problem of determining the optimal design of the connector assembly between the ceramic hull of a high-speed airplane and its metallic fuselage is presented. Definitions of the parameters that exert an effect on the bearing capacity of this assembly are given. An example illustrating the solution of the problem of finding the optimum of the parameters of a construction for the case of a three-layer axisymmetric model is presented.

High-temperature constructional powder steel and alloys

Strong new alloys based on intermetallic Fe-Cr-Al compounds and systems with strengthening by refractory nanoparticles may be used in heat-stressed components of high-speed airplanes and jet engines and in heat exchangers for the oil and atomic industries. Experiments confirm the high performance of such dispersely hardened materials. The small-scale production of hot-deformed components from dispersely hardened high-temperature ferritic ПX25Ю6 + 0.5% Y2O3 steel has been introduced.

SIMULASI GERAK DAN ANALISIS KESTABILAN KOPLING INERSIA WAHANA DIRGANTARA DENGAN BENTUK BADAN RAMPING

Inertia coupling is a motion phenomenon of a high-speed airplane having slender body and low aspect ratio. This inertia coupling happens when the aircraft performs a roll manoeuvre motion with a high roll rate. This paper will discuss the derivation of inertia coupling equations of motion, modelling equations of motion in the Matlab/Simulink software, simulating the dynamics motion, and analyzing the stability of the inertia coupling. Numerical simulation and stability analysis of the inertia coupling for a fighter aircraft will be presented in this paper. Keywords:Inertia coupling, Stability analysis, Flight simulation, Slender body

Testing the Limits: Aviation Medicine and the Origins of Manned Space Flight (review)

Reviewed by: Testing the Limits: Aviation Medicine and the Origins of Manned Space Flight Matthew H. Hersch (bio) Testing the Limits: Aviation Medicine and the Origins of Manned Space Flight. By Maura Phillips Mackowski . College Station: Texas A&M University Press, 2005. Pp. xii+289. $49.95. Almost immediately upon launching their first large rockets in the late 1940s, researchers in the United States and the Soviet Union stuffed the nose cones with a petting zoo's worth of animals just to see if they would survive the trip. The health of mice in space was not an idle concern in the years after World War II; physiologists preparing for World War III wondered which lethal mechanism—weightlessness, temperature, insanity—would fell future space pilots first. Soviet space dog Laika, a stray mutt launched into Earth orbit in November 1957, spent three days in abject terror, a feeding tube crammed down her throat, until she died of heat exhaustion. American researchers trained chimpanzees to mimic the human pilots who would soon follow them into space, pulling levers in pretend cockpits. Such experiments were only one small (and much-mocked) part of the research program of "aviation medicine," a field of study that, shortly before World War II, expanded from a fringe pursuit into a thriving international research discipline. Aviation medicine could not have found a better champion than Maura Phillips Mackowski; her new book, Testing the Limits, faithfully recounts the efforts of American and German research physicians who, at the dawn of the space age, saved more than a few pilots' lives by perfecting life-support equipment and quantifying the physiological and psychological effects of aviation. It is a telling statement about this [End Page 897] research that Mackowski follows it through personalities rather than institutions: in the mid-twentieth century, aviation medicine flourished under the stewardship of a handful of dedicated scientists who tirelessly lobbied skeptical superiors, scrounged for funds, and experimented on themselves. These pioneers include Harry Armstrong, who founded the first U.S. aeromedical research laboratory in 1934 at Wright Field in Dayton, Ohio, and his German counterpart, Hubertus "Struggie" Strughold, who, like the Führer, was a wonderful dancer. Germany's wartime experience with high-speed airplanes made its aviation physicians particularly valuable at war's end, and Strughold, the least Nazified of the group, found a warm reception in the United States when American spies smuggled him and many other scientists out of the Reich in Project Paperclip. In America, the "Paperclips" and native-born colleagues like Randy Lovelace and Paul Stapp established human tolerances for acceleration and altitude and the medical implications of transformative wartime technologies like ejection seats and rocket planes. American aviation medicine of the 1950s emerges in Testing the Limits as a research frontier populated by hands-on iconoclasts quite content to abuse their bodies for science, exposing themselves to supersonic wind blasts or jumping from stratospheric weather balloons. Some intrepid physiologists dreamed of taking their work literally to the Moon, but until the launch of Sputnik in October 1957, space remained a dirty word in the air force, under whose auspices most American aviation physiologists worked. The years 1958 through 1961, however, quickly became space medicine's heyday, with the new National Aeronautics and Space Administration (NASA) calling on the physicians to help select the military pilots who would become America's first astronauts. Ultimately, though, NASA wanted the physiologists' reassurance, not their research. Mackowski is charitable toward the doctors, but their "examinations" were often worthless experiments masquerading as evaluative tests. As it turned out, nude anthropometric photography couldn't distinguish good pilots from bad ones, and aviation medicine's influence over astronaut selection quickly waned. Mackowski's final chapter, on the group of unqualified civilian women Lovelace unsuccessfully promoted as potential astronauts in 1961, reveals, ultimately, only the physiologist's naivete about the military foundations of "big science." Testing the Limits is a thoroughly researched work making excellent use of archives and oral history; only Soviet space medicine is noticeably shortchanged. Mackowski's account resounds with the kind of thrilling stories for which basic cable was invented, but evaluating aviation medicine's scientific legacy remains tricky. Nazi experiments were...

The relevance of economic data in the decision-making process for orbital launch vehicle programs, a U.S. perspective

Over the past fifteen years, major U.S. initiatives for the development of new launch vehicles have been remarkably unsuccessful. The list is long: NLI, SLI, and X-33, not to mention several cancelled programs aimed at high speed airplanes (NASP, HSCT) which would share some similar technological problems. The economic aspects of these programs are equally as important to their success as are the technical aspects. In fact, by largely ignoring economic realities in the decisions to undertake these programs and in subsequent management decisions, space agencies (and their commercial partners) have inadvertently contributed to the eventual demise of these efforts. The transportation revolution that was envisaged by the promises of these programs has never occurred. Access to space is still very expensive; reliability of launch vehicles has remained constant over the years; and market demand has been relatively low, volatile and slow to develop. The changing international context of the industry (launching overcapacity, etc.) has also worked against the investment in new vehicles in the U.S. Today, unless there are unforeseen technical breakthroughs, orbital space access is likely to continue as it has been with high costs and market stagnation. Space exploration will require significant launching capabilities. The details of the future needs are not yet well defined. But, the question of the launch costs, the overall demand for vehicles, and the size and type of role that NASA will play in the overall launch market is likely to influence the industry. This paper will emphasize the lessons learned from the economic and management perspective from past launch programs, analyze the issues behind the demand for launches, and project the challenges that NASA will face as only one new customer in a very complex market situation. It will be important for NASA to make launch vehicle decisions based as much on economic considerations as it does on solving new technical challenges.

High-Speed Dreams: NASA and the Technopolitics of Supersonic Transportation, 1945-1999 (review)

Reviewed by Virginia P. Dawson High-Speed Dreams: NASA and the Technopolitics of Supersonic Transportation, 1945–1999. By Erik M. Conway. Baltimore: Johns Hopkins University Press, 2005. Pp. xvii+369. $49.95. Erik Conway has aptly titled his history of American efforts to develop supersonic-transport aircraft High-Speed Dreams to underscore the past century's infatuation with speed as a symbol of Western technical progress. He focuses on three American efforts to develop an SST and shows how national security, environmental concerns, and market forces provided the rationale for decisions at different points in the story. What makes his account particularly valuable is his ability to provide the economic, social, and political context for the technology he describes. Conway seems to have struck the right balance between attention to the nuts-and-bolts of aircraft design and discussion of the larger issues, particularly state support for advanced technology. The book's prize from the American Institute for Aeronautics and Astronautics is well deserved. The first effort to develop a high-speed airplane began during the late 1950s as a military project. However, when the development of advanced missile technology obviated the need for a supersonic bomber, the dreams of aircraft designers were transferred to the commercial arena. By the early 1960s, proponents of an American SST used not only its propaganda value in the cold war, but also the need to compete with a state-supported consortium of European manufacturers that was developing the Concorde, to justify its funding. Conway suggests that the cancellation of the American SST as a result of anti-sonic-boom environmentalists is only half the story. By 1971, Boeing's profitability was eroding, and it seemed clear that the SST would never prove economically viable. More important, Airbus Industrie, formed by the European consortium, threatened the American monopoly in the subsonic aircraft market. The SST had become an unwelcome diversion from the development of more competitive, if slower, aircraft. Surprisingly, given the aerospace industry's lukewarm support, NASA received political and financial backing for a relatively small effort to develop a supersonic airplane. The Advanced Supersonic Transport (AST) program, later renamed the Supersonic Cruise Aircraft Research (SCAR) program, was cancelled by the Reagan administration in 1981 as an example of "corporate welfare." Nevertheless, this program provided funding for important scientific investigations into the depletion of the ozone layer. During the 1990s, NASA and the aircraft industry tried one last time to realize their high-speed dreams. The new plane, dubbed the "Orient Express" because it was to put Asian markets within a few hours of the American continent, was proposed as a means to trump Europe's next-generation SST, the "Concorde II." It too was cancelled. [End Page 866] Conway concludes his star-crossed history of America's infatuation with high speeds by offering a perceptive analysis of the incompatibility of the technologist's belief in unlimited progress and the environmentalist's stress on the need to accept limitations in order to save the earth's resources for future generations. He points out that the demise of the American SST is connected to the rise of the "free market" ideology of the 1980s and 1990s. Markets, he points out, never drive the development of very large and expensive technological projects: "Only the state has the ability to fund the grand techno-dreams of aerospace enthusiasts, be they supersonic/ hypersonic transports, air-breathing launch vehicles for routine space access, giant orbiting solar-power stations, or the like" (p. 305). To disentangle the various forces that beset the three American efforts to develop supersonic-transport aircraft, Conway has made excellent use of documents from many archival collections, including the Boeing Company (one of the few aircraft manufacturers with a publicly accessible collection), the National Archives, NASA Research Center, the Sierra Club, and presidential libraries. For his early chapters, in addition to archival material, Conway had excellent secondary sources to draw upon, including a body of work...

Robert T. Jones, One of a Kind

His contemporaries saw R.T. Jones as one of the notably creative aerodynamicists of the twentieth century. This essay reviews his remarkable life and career, including his years as a farm-country boy, college dropout, and fledgling airplane designer in Missouri, his time as an elevator operator and self-directed student in Washington, D.C., and his long professional career as an aerodynamicist at the Langley and Ames Aeronautical Laboratories and Stanford University. The focus in his career is on his fundamental discovery of the benefits of sweepback for the wings of high-speed airplanes. This includes speculation about his highly intuitive thought processes in arriving at his creative ideas. I also give an account of his work on blood flow and the mechanical heart, his avocational accomplishments as a maker of telescopes and violins, and his philosophical interest in human affairs.

吸い込みによる後退翼面上の境界層遷移の制御

The behavior of three-dimensional boundary layer on swept wings is an important research subject for the future high-speed airplane. The purpose of the present paper is to study controllability of boundary layer transition by suction. Experiments are done by using a closed circuit wind tunnel at Tokai University. The swept wing model with a latch for variable sweep angle at a root is mounted vertically in the 1.5m×1.0m test section. Suction is applied through the perforated surface, and flow velocity of the suction is variable. Two velocity components measured by the twodimensional hot wire anemometer with computer controlled three-dimensional traverse system. At various sweep angles, the velocity inside the boundary layer is measured, and the data are investigated to obtain the relation between the sweep angle and the effect of suction.

Nonlinear hyperbolic differential equations in microelectronics

Nonlinear hyperbolic differential equations have been a subject of intense research in the field of gas dynamics due to many engineering problems associated with high-speed airplanes, missiles, materials processing, etc. Recently, phenomena known from gas dynamics are found to occur also in the microeletronic devices such as MOSFET. Here a few interesting mathematical problems are presented along with future areas of research.

Application of leading-edge vortex manipulations to reduce wing rockamplitudes

HE extension of an airplane's performance envelope into the high angle-of-attack region to improve maneuverability often carries the penalty of undesirable instabilities. One frequently encountered lateral instability is the limit-cycle roll oscillation, rock, which is driven by strong, concentrated vortices originating from the leading edges of highly swept lifting surfaces.!~8 Mathematical models917 at various levels of complexity have clarified the role of these vortices in driving the rolling motion. Simultaneously accumulated experimental evidence18-19 indicates that a wing's rolling moment can be affected by mechanical or pneumatic manipulation of these vortices. Since these vortices generate the much needed high-lift coefficients at larger angles of attack, it is logical to assume that control of this undesirable roll oscillation is possible by manipulating the strength and/or location of the vortices1820 that cause the wing rock. In the present study, a simple flap system was incorporated into the front section of a slender double-delta wing where the leading-edge vortex motion could be influenced by moving these flaps (Fig. 1). Since analytical studies21 on the control of wing rock indicate that a feedback of the roll oscillation rate, or a frequency shift between the wing motion and the control device, can generate damping of the motion, the proposed flap system was activated (mechanically) at the same frequency of the rolling motion. Also, instead of feeding back the roll rate, a relative phase shift (between the oscillatory motions of the flaps and wing) was imposed due to the mechanical simplicity required for such a wind-tunnel model. Experimental Apparatus A schematic description of the free-to-roll wind-tunnel model is shown in Fig. 1 (top) and additional geometrical details of the model are provided in the bottom of Fig. 1. Each leading-edge flap was mounted on two roller bearings to reduce friction, and the size of these bearings dictated the wing thickness. Intuitively, the flaps should have been placed at the most forward position, starting at the apex, but because of the large size of the bearings the flaps were moved approximately 45% of the chord behind the appex. Consequently, to increase the likelihood of being able to manipulate leading-edge vortex location by such simple leading-edge flap deflections, a double-delta wing shape was used. This choice is based on experimental evidence2224 indicating that a second vortex forms near the leading-edge break point and, therefore, the flaps were placed behind this point. (As most highspeed airplanes have thin, highly swept strakes that cannot house movable control surfaces, the above placing permits

MEASUREMENT AND PREDICTION OF DEPOSITIONAL ACCURACY IN DISPERSANT SPRAYING FROM LARGE AIRPLANES

ABSTRACT Aerial application of dispersants has progressed to include very large airplanes, such as the Hercules C-130, for which a portable spray unit has been developed. This unit, which can be rapidly placed in the cargo aircraft (without any mechanical alterations) was flight tested with spraying of a dispersant concentrate in 1982. The tests measured actual deposition of chemical under various conditions. The most definitive data were collected using a “deposition track,” positioned on the ground across the flight path of the airplane. The dyed dispersant was recovered from this track and the data converted to amount per unit area, and to percent of total pumped fluid on-target. The results led to correlation of depositional accuracy in terms of the air shear experienced by the sprayed fluid. The data has been further used to develop a mathematical prediction for design of dispersant treatment procedures using high-speed airplanes. Use of these considerations in operational planning can improve dispersant dosage control by preventing both under-treatment and wasteful off-target drift.

Development of a BLC high-lift system for high-speed airplanes.

This paper presents the significant steps in the development of a boundary-layer control (BLC) high-lift system for the 367-80 (707 prototype) airplane. The design is based on an advanced boundary-layer control concept using an ejector for momentum augmentation of BLC air and primary air bleed from the propulsion system. A modulated thrust reverser for flight-path control has been integrated into the over-all design. Considerations leading to the selection of the design concept are discussed, and the importance of a well integrated program of aerodynamic and mechanical system development is shown. Pertinent results of research involving two-dimensional and complete configuration tests in the wind tunnel and full-scale ejector tests in the laboratory are given. A recently completed, joint flight research program by Boeing and NASA shows that large gains in low-speed performance can be made with blowing boundary-layer control. Landing speeds less than 85 knots at 140,000 Ib airplane gross weight have been consistently achieved. Careful flight evaluation shows that conventional aerodynamic controls with stability augmentation can provide satisfactory handling characteristics for large jet airplanes throughout the extended low-speed flight envelope.

高速機体の外板特に,翼型変形に及ぼす飛行荷重と空力加熱の影響について

The deformations of the wing-sections and the stressed-skins of a high speed airplane will give a great effect on it's aerodynamic performance. In this second report based on the first report [1] already published, the deflection of a skin panel subjected to flight and thermal loads is analysed, and the equation with which the skin thickness needed to fulfil the requirements of allowance for the variations of a wing section can be calculated is presented. As one of the results, it is found that the aerodynamic requirements such that the forms of wing sections should be kept accurately within some allowance of deformation might often become considerably severe in the design of skin panel and the effect of elastic deformations should carefully be considered.

Thermal Buckling of Circular Cylindrical Shells Under Circumferential Temperature Gradients

The thermal buckling of thin-walled circular cylindrical shells due to axial stresses caused by variations in temperature around the circumference is analyzed. This problem is of considerable importance in the structural design of high-speed airplanes and missiles, since they are subjected to high rates of aerodynamic heating. The analysis is performed with the aid of Donnell's equations, which can be shown to be satisfactory for the problem under consideration. The variation of the thermal stress with the circumferential coordinate is represented by Fourier series; the stresses are assumed constant through the thickness and in the axial direction. The conclusion reached is that the axial buckling stress under variable thermal stress conditions is close to the critical stress of the cylinder when it is subjected to uniform axial compression, if the variation of the intensity of the thermal stress is not large within a half-wavelength of the buckling pattern.

高速機機体の外板の変形に及ぼす飛行荷重と熱応力の影響について

高速機機体の外板の変形に及ぼす飛行荷重と熱応力の影響について

The Human Pilot and the High-Speed Airplane

A s AIRCRAFT ATTAIN higher and higher speeds, the •*• ** ability of the human pilot to maintain control becomes marginal in some cases. Recognizing tha t pilot-induced oscillations of large magnitude have been experienced in high-speed low-altitude flight, it is necessary to predict accurately whether the pilot will be able to achieve stable flight with a particular aircraft. Consequently, analytical expressions, which interpret the dynamic characteristics of a human pilot, are needed for stability analysis. Investigations of pilot response which provide data on such physiological factors as reaction t ime and muscular lag have been supported by both the United States Air Force and Navy Bureau of Aeronautics. Under specific test conditions experimental da ta establishing human transfer functions have been obtained. Some of these investigations have taken place at the Franklin Inst i tute, Goodyear Aircraft, and Langley Field, and their findings are included in reference 2. The purpose of the present s tudy is to investigate human dynamics as it affects the airplane in pitch, and to present a means of predicting the pilot transfer function during pitching flight. In detailing the longitudinal stability of a human pilot-aircraft combination, the type of control the pilot a t tempts to apply has been rationalized, and the physiological factors of reaction time and muscular lag have been included.

The Reduction of Flight-Test Performance Data to Standard Air Conditions by the Temperature Altitude Method

Analysis of flight performance results on modern high-speed airplanes has shown that currently used methods for the correction of observed performance to standard air conditions are inadequate. Present methods have been derived on the assumption that the compressibility of air is negligible, and therefore unsatisfactory results have been obtained in applying such methods to airplanes flying at Mach Numbers of approximately 0.6 and above. A new method for the reduction of observed flight data is suggested herein, in which allowance is made for Mach Number effects on the aerodynamic characteristics of the airplane and propeller and on the thermodynamic characteristics of the engine. This new method is called the method, since the observed performance is corrected for the deviation in atmospheric pressure from the standard pressure corresponding to the observed air temperature. The method is applicable to airplanes driven by Otto cycle engines and propellers, by gas-turbine engines and propellers, by gas-turbine jet propulsion engines, and by combinations of these types of engines. Although intended principally for highspeed airplanes, the method is applicable to airplanes of all speed classes from low Mach Numbers up to and including supersonic flight velocities. The analysis and proof of the temperature altitude method are somewhat lengthy, but the routine application of the method to the reduction of observed flight data is of extreme simplicity. Use of the method should result in improved correlation of highspeed flight performance data.

A Simple Method of Applying the Compressibility Correction in the Determination of True Air Speed

By reviewing the complete impact pressure equation, which describes the pressure exerted by an air stream upon coming to rest, it is shown that the approximating assumption that is involved in the customary method of determining the true air speed of an airplane at altitude is no longer satisfactory for high-speed airplanes. The compressibility error that is a result of this assumption is isolated, and a method is described whereby the necessary correction may be applied by constructing additional altitude curves of indicated air speed (V\/<r) on the conventional air-speed indicator calibration chart. The true air speed at any altitude is then determined by the usual method—from the known value of indicated air speed and atmospheric pressure and temperature. The error that results if the compressibility correction is not applied is shown to be + 1 1 m.p.h. for a 400-m.p.h. airplane at 25,000 ft. altitude. The method here presented for applying the compressibility correction is less cumbersome than other suggested methods and has the additional advantage of retaining the use of the customary air-speed indicator calibration chart. Finally, the possible effect of compressibility on the position error of a pitot-static head installation is briefly analyzed and discussed, and the difficulties encountered in determining true atmospheric pressure and temperature in high-speed flight are mentioned.