Real-Time Trajectory Generation via Task Space Velocity Blending
This paper presents a new velocity blending approach to the problem of task space trajectory generation.
trajectory generation velocity blending↗
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Mass Estimation Relationships for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures
Blended-Wing-Body (BWB) achieve a higher L/D than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible through advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB, sufficient historical data does not exist for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes general parametric Mass Estimation Relationships (MERs) based on high fidelity finite element analysis using PRSEUS for estimating the weight of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, and take-off gross weight.
BWB↗
Mass Estimation Relationship for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures
Blended-Wing-Body (BWB) aircraft concepts achieve higher lift-to-drag ratios (L/D) than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible using advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB configuration, sufficient historical data is not readily available for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes a general parametric Mass Estimation Relationship (MER) based on high fidelity Finite Element Analysis (FEA) using PRSEUS for conceptual weight estimation of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, span ratio, and take-off gross weight as parametric design variables.
PRSEUS↗
Mass Estimation Relationship for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures
Blended-Wing-Body (BWB) aircraft concepts achieve higher lift-to-drag ratios (L/D) than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible using advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB configuration, sufficient historical data is not readily available for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes a general parametric Mass Estimation Relationship (MER) based on high fidelity Finite Element Analysis (FEA) using PRSEUS for conceptual weight estimation of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, span ratio, and take-off gross weight as parametric design variables.
BWB↗
Surface topography of single crystals of face-centered-cubic, body-centered-cubic, sodium chloride, diamond, and zinc-blende structures
Surface topography of single crystals of face- centered-cubic, body-centered-cubic, sodium chloride, diamond, and zinc blende structures
SODIUM CHLORIDE↗
High-lift characteristics of a variable-sweep supersonic transport model with a blended engine-fuselage and engine-mounted horizontal tails
High lift characteristics of variable-sweep transport model with blended engine-fuselage and engine-mounted horizontal tails
VARIABLE SWEEP↗
Cold consolidation of metal plus dispersoid blends for examination by electron microscopy
Feasibility of high-energy-rate compaction to consolidate powder blends used in preparation of dispersion-strengthened alloys
METALLURGY↗
Comparison of selected submicron powder blending methods for dispersion alloys
Wet and dry blending nickel-aluminum oxide submicron powders for dispersion-strengthened alloys
POWDERED METAL↗
Low-speed characteristics of a variable-sweep supersonic transport model with a blended engine fuselage and engine-mounted tails
Low-speed characteristics of variable-sweep supersonic transport model with blended engine fuselage and engine-mounted tails
FLIGHT CHARACTERISTICS↗
Electron microscopy technique for determination of dispersoid distribution in powder blends
Electron microscopy technique for determining dispersoid distribution in powder blends
Buzek, B. C.↗
Low-subsonic aerodynamic characteristics of a space shuttle-orbiter concept with a blended delta wing-body
Low subsonic aerodynamic characteristics of space shuttle-orbiter concept with blended delta wing-body
Freeman, D. C., Jr.↗
Subsonic stability, control, and performance of a shuttle concept with a blended wing-body
Subsonic stability, control, and performance of shuttle concept with blended wing-body
Fox, C. H., Jr.↗
Effect of configuration modifications on the low-subsonic aerodynamic characteristics of a space shuttle orbiter concept with a blended delta wing-body
An investigation of several configuration modifications to improve the subsonic stability and performance of a blended delta wing-body space shuttle-orbiter concept has been conducted in the Langley low-turbulence pressure tunnel. These modifications included variations in vertical-tail location and orientation, wing planform shape, and afterbody shape. The model was tested at a Reynolds number, based on body length, of 17 x one million, at a Mack number of 0.25, and at angles of attack from about -4 deg to 22 deg.
Freeman, D. C., Jr.↗
Low-speed wind-tunnel tests of a large scale blended arrow advanced supersonic transport model having variable cycle engines and vectoring exhaust nozzles
A low-speed wind-tunnel investigation was conducted in a full-scale tunnel to determine the performance and static stability and control characteristics of a large-scale model of a blended-arrow advanced supersonic transport configuration incorporating variable-cycle engines and vectoring exhaust nozzles. Configuration variables tested included: (1) engine mode (cruise or low-speed), (2) engine exit nozzle deflection, (3) leading-edge flap geometry, and (4) trailing-edge flap deflection. Test variables included values of C sub micron from 0 to 0.38, values of angle of attack from -10 degrees to 30 degrees, values of angle of sideslip, from -5 degrees to 5 degrees, and values of Reynolds number, from 3.5 million to 6.8 million.
Parlett, L. P.↗
Low-speed wind-tunnel tests of a one-tenth-scale model of a blended-arrow advanced supersonic transport
Tests were conducted in the Langley full scale tunnel to determine the low-speed aerodynamic characteristics of a 1/10 scale model of a blended-arrow advanced supersonic transport. Tests were made for the clean configuration and a high-lift configuration with several combinations of leading- and trailing-edge flaps deflected for providing improved lift and longitudinal stability in the landing and takeoff modes. The tests were conducted for a range of angles of attack from about -6 deg to 30 deg, sideslip angles from -5 deg to 10 deg, and for Reynolds numbers from 6.78 x 1,000,000 to 13.85 x 1,000,000 corresponding to test velocities of 41 knots to 85 knots, respectively.
Lemore, H. C.↗
Low speed wind tunnel tests of 1/10-scale model of a blended-arrow supersonic cruise aircraft
Low speed static force tests have been conducted in a full scale tunnel to determine the low speed aerodynamic characteristics of a 1/10-scale model of a blended-arrow supersonic cruise aircraft. A clean configuration and a high lift configuration with several combinations of leading- and trailing-edge flaps to provide improved lift and longitudinal stability in the landing and takeoff modes were used. The tests were made at angles of attack from about -6 deg to 30 deg, sideslip angles from -5 deg to 10 deg, and Reynolds numbers from 6.78 x 1 million to 13.85 x 1 million corresponding to test velocities of 41 to 85 knots.
Mclemore, H. C.↗
Custom blending of lamp phosphors
Spectral output of fluorescent lamps can be precisely adjusted by using computer-assisted analysis for custom blending lamp phosphors. With technique, spectrum of main bank of lamps is measured and stored in computer memory along with emission characteristics of commonly available phosphors. Computer then calculates ratio of green and blue intensities for each phosphor according to manufacturer's specifications and plots them as coordinates on graph. Same ratios are calculated for measured spectrum. Once proper mix is determined, it is applied as coating to fluorescent tubing.
Klemm, R. E.↗
Aerodynamic characteristics at Mach numbers of 1.5, 1.8, and 2.0 of a blended wing-body configuration with and without integral canards
An exploratory, experimental, and theoretical investigation was made of a cambered, twisted, and blended wing-body concept with and without integral canard surfaces. Theoretical calculations of the static longitudinal and lateral aerodynamic characteristics of the wing-body configurations were compared with the characteristics obtained from tests of a model in the Langley Unitary Plan wind tunnel. Mach numbers of 1.5, 1.8, and 2.0 and a Reynolds number per meter of 6.56 million were used in the calculations and tests. Overall results suggest that planform selection is extremely important and that the supplemental application of new calculation techniques should provide a process for the design of supersonic wings in which spanwise distribution of upwash and leading-edge thrust might be rationally controlled and exploited.
Robins, A. W.↗