The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program executed by the Air Force Research Laboratories (AFRL) and Australian Defence Science and Technology Organization (DSTO). HIFiRE flight 5 is devoted to measuring transition on a three-dimensional body. This paper summarizes payload configuration, trajectory, vehicle stability limits and roughness tolerances. Results show that the proposed configuration is suitable for testing transition on a three-dimensional body. Transition is predicted to occur within the test window, and a design has been developed that will allow the vehicle to be manufactured within prescribed roughness tolerances

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HIFiRE-5 Flight Vehicle Design

Potential applications of a counterflow drag-reduction technique were investigated to assess performance improvements on aerospace vehicles. The motivation for this study was the 30-50% drag reduction achieved by counterflow blowing experiments on hemispherical cylinders at Mach 4 and higher. Exploratory studies indicate that drag improvements by counterflow drag reduction on hemispherical bodies cannot match those of aerodynamically shaped sharp-nosed bodies. Hence, the approach taken in the present study is that for hypersonic Mach numbers: if the nose shape is required to be blunt for considerations other than drag, counterflow blowing can be effective in improving the performance of the system. Although for generic body shapes counterflow blowing is most effective for blunt-nosed bodies, when applied to actual systems, many other factors need to be considered, such as available internal volume and extreme compressed carriage requirements. Depending on the vehicle speed and nose shape, estimated drag reductions of 15-30% were applied to predict the overall performance gains on Space Operations Vehicle, Gun-Launched Rocket, and Pegasus XL configurations. Potential savings in propellant and improvements in burnout velocity and range are reported. For launch systems with high fuel fraction, the payoff with counterflow drag reduction is marginal as the overall effects of aerodynamic drag on performance are small in the upper atmosphere. For the lower fuel fraction vehicle, the Gun Launched Rocket, a range improvement of 7% was achieved for a drag reduction of 30% with 0.3 blunting of nose flying above Mach 3; with greater blunting, however, the volume of fuel cannot compensate for the increase in drag.

Applications of a Counterflow Drag Reduction Technique in High-Speed Systems

The use of computer programs driven by genetic algorithms has become an increasingly popular method for optimizing engineering designs. This paper focuses on the modeling and optimization of liquid-rocket-enginepropelled missiles with a computer program that is composed of a series of codes that simulate the performance of liquid-propelled rockets andare controlledby a genetic algorithm.Because the entiremissile design is considered, the complete system performance must be modeled accurately and efficiently. The methodology described in this paper has been extended to both the preliminary design and reverse-engineering of liquid-propelled missiles. The performance model has been validated against the performance of a liquid-propelled missile and the results are provided. Two different fast-aerodynamic-prediction codes are used and their results are compared. A complete preliminary design of a liquid-propelled missile system is considered with a variety of goals and constraints. Results from the preliminary design optimization are also shown and discussed in detail.

Genetic-Algorithm Optimization of Liquid-Propellant Missile Systems

The USAF Missile Datcom is an industry standard tool used for predicting the aerodynamics of conventional missile configurations. Typical aerodynamic models are constructed from wind tunnel data and used to simulate the flight profile and behavior of a missile. However, certain configurations require data beyond the usual 20 degrees angle of attack obtained in the wind tunnel. Comparisons have been made with existing subsonic high angle of attack wind tunnel data in order to assess Datcom’s capabilities in predicting the aerodynamics of a configuration to angles of attack in excess of 20 degrees. Results presented herein indicate that Missile Datcom can reasonably predict the aerodynamics of standard body, fin, and body-fin configurations to angles of attack up to 90 degrees.

/pdf/high-angle-of-attack-aerodynamic-predictions-using-missile-31nodjoemc.pdf

High Angle of Attack Aerodynamic Predictions Using Missile Datcom

The advantages and disadvantages of the various methods for air launching expendable or reusable space launch vehicles are described. Many different air launch scenarios are modeled and simulated using trajectory optimizations. The trajectory optimization is conducted using POST, a numerical integration program based on the three-degree-of-freedom equations of motion of a flight vehicle. Results in terms of change in velocity gains are reported as a function of launch conditions and launch vehicle aerodynamics. Air launch benefits are presented for a range of air speeds, altitudes, and flight path angles. The most beneficial launch vehicle parameters are in the following order; launch velocity, launch flight path angle, and launch altitude. Increasing launch vehicle size had the largest effect on payload size. There is an optimum launch flight path angle that maximizes the benefit from air launching. The results show that once above about 15000 meters (49,200 feet), added launch altitude has little additional benefit. Nomenclature Ae = Nozzle exit area = Angle of attack β =

Air Launching Earth-to-Orbit Vehicles: Delta V gains from Launch Conditions and Vehicle Aerodynamics

: In missile preliminary design it is necessary to quickly and economically estimate the aerodynamics of a wide variety of missile configuration designs Since the ultimate shape and aerodynamic performance are so dependent upon the subsystems used, such as payload size, propulsion system selection and launch mechanism, the designer must be capable of predicting a wide variety of configurations accurately The fundamental purpose of Missile Datcom is to provide an aerodynamic design tool which has the predictive accuracy suitable for preliminary design, and the capability for the user to easily substitute methods to fit specific applications

http://www.dtic.mil/dtic/tr/fulltext/u2/a237817.pdf

Missile Datcom. User's Manual - Rev 4/91

: Development of a Missile DATCOM handbook and computer program is described. The type of methods investigated as well as a method selection rationale is discussed. Methods were selected for predicting the aerodynamics of missile configurations made up of circular, elliptic or arbitrary bodies with or without fins an inlets. These methods predict static and dynamic stability derivatives and are suitable for preliminary design. A summary of the comparisons of many results with experimental data is included. Keywords: Computer aided design, DATCOM computer program, FORTRAN, Subsonic, Transonic, Supersonic, Hypersonic.

Missile DATCOM. Volume 1

: The computer code is capable of addressing a wide variety of conventional missile designs. For the purposes of this document, a conventional missile is one which is comprised of the following: An axisymmetric or elliptically-shaped body, One to four fin sets located along the body between the nose and base. Each fin set can be comprised of one to eight identical panels attached around the body at a common longitudinal position, and An airbreathing propulsion system. To minimize the quantity of input data required, commonly used values for many inputs are assumed as defaults. However, all program defaults can be over-ridden by the user in order to more accurately model the configuration of interest.

Steven R. Vukelich

Papers

Missile Datcom. User's Manual - Rev 4/91

Missile DATCOM. Volume 1

Missile Datcom. Volume 2. User's Manual