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The separation computation of arcs for optimal flight paths with state variable inequality constraints.
Maximum trajectory for glider entering earth atmosphere at supercircular velocity, subject to maximum altitude constraint
Wing deployment method and apparatus Patent
Method for deployment of flexible wing glider from space vehicle with minimum impact and loading
Approximate optimal atmospheric entry trajectories
Reentry glider approximate optimal atmospheric entry trajectories for maximizing function of terminal velocity, altitude, flight path and heading angle under terminal nonlinear constraints
Approximate optimal atmospheric entry trajectories.
For a reentry glider, approximate solutions are found in closed form for the problem of maximizing a function of the terminal velocity, altitude, flight-path angle and heading angle subject to, at most, three terminal nonlinear constraints. The results given here extend the previous results in two important ways: (1) the second-order approximation of the entry dynamics of Loh is used instead of the first-order approximation of Allen and Eggers. This approximation is found to compare extremely well with an exact numerical optimal path. (2) A three-dimensional optimization problem is solved which includes Loh's second-order approximation where the roll angle as well as the lift coefficient are determined subject to constraints which include the terminal heading angle. Furthermore, closed-form solutions can also be obtained subject to in-flight constraints on the lift coefficient and roll angle.
Flexible wings for transportation.
The possible uses of flexible wings for transportation of passengers and cargo from point to point on earth are discussed along with emergency applications of flexible wings in connection with conventional aircraft. Topics considered include gliding and soaring as a sport, towing of flexible-wing gliders for cargo delivery, powered flight with small aircraft having folding flexible wings, aerial dropping of personnel and cargo on flexible wings instead of parachutes, landing and recovery of rocket payloads by means of flexible wings, and use of flexible wings with ejection seats and as an emergency landing system for conventional aircraft.
Motorless flight research, 1972
The proceedings of a symposium on motorless flight research are presented. The subjects discussed are: (1) glider aerodynamic and design, (2) instrumentation, (3) structural concepts and materials, (4) soaring meteorology, (5) self-launching and ultralight sailplanes, and (6) performance testing.
Study of the feasibility of using a sailplane as an instrument platform for the study of wake vortex phenomena
The feasibility of utilizing instrumentation mounted on a sailplane wing is investigated to determine vortex wakes from a large aircraft. The instrumentation consisted of static and total pressure tubes and a rotating vane vorticity meter mounted in a pod on the glider wing tip. It was concluded that the study was not feasible.
Excitation of a Helmholtz resonator by a turbulent boundary layer
A turbulent boundary layer on the fuselage of a glider was used to excite a Helmholtz resonator. The resonator orifice was flush with the surface and smaller than the boundary layer thickness. Resonator frequencies were chosen so they would tune with different portions of the boundary layer wall pressure spectrum. The resonators were excited at both the Helmholtz frequency and a standing wave frequency. The results show a shift in the Helmholtz frequency when the boundary layer is present. This shift indicates the degree to which the turbulence interacts with the acoustic motion in the orifice and modifies the end correction. Four of the nine resonators tested were 'strongly' excited and radiated considerable acoustic sound. This phenomenon occurs when turbulent eddies about the size of the orifice are convected past the orifice with the proper velocity to impose a frequency that matches a resonant frequency of the resonator. Turbulent eddies which are either smaller or larger than the orifice will not produce strong excitation.
Excitation of a Helmholtz resonator by a turbulent boundary layer
A turbulent boundary layer on the fuselage of a glider is used to excite a Helmholtz resonator whose openings are comparable in size to the turbulent eddies in the boundary layer. The resonator was excited at both the Helmholtz frequency and a standing wave frequency. The level of the resonator response and the response frequency are the major results. A shift in the response frequency, compared to acoustic excitation, indicates an interaction of turbulent and acoustic motions and a modification of the orifice end correction. A strong excitation phenomenon occurs when the resonator and boundary layer are tuned, in which case turbulent eddies of about the orifice diameter in size flow past the orifice and impose a frequency equal to one of the resonant frequencies of the resonator.
The Silver Bird story: A memoir
A manned recoverable flying machine that operates both in air and space was discussed. This space shuttle precursor was proposed in the early 1900's by Eugen Sanger. The vehicle was especially to be used as the first stage of booster rockets or to ferry, supply and furnish rescue equipment for manned space stations. Basic concepts of the space aircraft, a cross between a powered booster rocket and an aerodynamic glider, are presented.
Experimental research and design planning in the field of liquid-propellant rocket engines conducted between 1934 - 1944 by the followers of F. A. Tsander
The development of the following Liquid-Propellant Rocket Engines (LPRE) is reviewed: (1) an alcohol-oxygen single-firing LPRE for use in wingless and winged rockets, (2) a similar multifiring LPRE for use in rocket gliders, (3) a combined solid-liquid propellant rocket engine, and (4) an aircraft LPRE operating on nitric acid and kerosene.
Two hundred years of flight in America: A bicentennial survey
The first recorded balloon ascension in America took place on June 19, 1784, when an unmanned balloon was raised in a public demonstration at Bladensburg, Maryland. On June 24, 1784, a thirteen-year-old boy ascended in the same balloon. The history of actual flight during the nineteenth century was entirely concerned with balloons except for several gliders and models leading to the coming of the airship and the aircraft. The history of practical flight in America begins in the twentieth century. The described developments related to aerostatics are concerned with balloons, rigid airships, and blimps. In a review of the evolution of aeronautics, attention is given to general aviation and its search for a market, trends in military aeronautics, and commercial aviation. It is pointed out that American air transport had its birth on New Year's Day, 1914, at Tampa Bay, Florida. The evolution of astronautics during the period from 1957 to 1976 is also examined, taking into account scientific satellites, the Apollo project, the exploration of the planets with the aid of unmanned spacecraft, strategic reconnaissance satellites, missile alarm satellites, instrumental satellites for detecting nuclear and thermonuclear explosions, weather satellites, communications satellites, and earth resource survey and geodetic satellites.
Wing shape optimization for maximum cross-country speed, with mathematical programming
A computer program was developed to calculate numerically the speed and circling polars of an aircraft when the lift and drag characteristics of the wing airfoils are known. The planform of the wing is described by variables which are optimized so that the cross-country speed of the glider is maximum for the particular type of thermal model. Two thermal models are compared and shown that with a greater wing area than now normally used the performance can be increased.
Design of Propellers for Motorsoarers
A method was developed for the design of propellers of minimum induced loss matched to an arbitrary operating point characterized by disc loading (thrust or power), air density, shaft speed, flight speed, and number of blades. A consistent procedure is outlined to predict the performance of these propellers under off design conditions, or to predict the performance of propellers of general geometry. The examples discussed include a man powered airplane, a hang glider with a 7.5 kW (10 hp) 8,000 rpm engine, and an airplane-like motorsoarer.
Science and Technology of Low Speed and Motorless Flight. Third International Symposium
Low speed aerodynamics of sailplanes and hang gliders are discussed. Emphasis is placed on optimal flight techniques, structures and materials, and ultralight design.
Balance training of the equilibrium organ and its effect on flight strategy
An experimental program was conducted with the pendular platform of the Oto-Rhino-Laryngology Clinic, which was developed for the investigation of disturbances of the equilibrium. The equilibrium sense of the glider pilot was emphasized. Results are presented.
A Monte Carlo approach to competition strategy
Variables taken into account in glider flight strategy decisions are modeled. These include height of clouds, distance between thermals, time of day, water ballast, present altitude, weather changes, lift organization, and distance to goal, as well as the strength of the next thermal. Results of the Monte Carlo atmospheric model are discussed.