1,138 research outputs found
Experimental evaluation of two turning vane designs for fan drive corner of 0.1-scale model of NASA Lewis Research Center's proposed altitude wind tunnel
Two turning vane designs were experimentally evaluated for corner 2 of a 0.1 scale model of the NASA Lewis Research Center's proposed Altitude Wind Tunnel (AWT). Corner 2 contained a simulated shaft fairing for a fan drive system to be located downstream of the corner. The corner was tested with a bellmouth inlet followed by a 0.1 scale model of the crossleg diffuser designed to connect corners 1 and 2 of the AWT. Vane A was a controlled-diffusion airfoil shape; vane B was a circular-arc airfoil shape. The A vanes were tested in several arrangements which included the resetting of the vane angle by -5 degrees or the removal of the outer vane. The lowest total pressure loss for vane A configuration was obtained at the negative reset angle. The loss coefficient increased slightly with the Mach number, ranging from 0.165 to 0.175 with a loss coefficient of 0.170 at the inlet design Mach number of 0.24. Removal of the outer vane did not alter the loss. Vane B loss coefficients were essentially the same as those for the reset vane A configurations. The crossleg diffuser loss coefficient was 0.018 at the inlet design Mach number of 0.33
Experimental evaluation of corner turning vanes
Two types of turning vane airfoils (a controlled-diffusion shape and a circular arc shape) have been evaluated in the high-speed and fan-drive corners of a 0.1-scale model of NASA Lewis Research Center's proposed Altitude Wind Tunnel. The high-speed corner was evaluated with and without a simulated engine exhaust removal scoop. The fan-drive corner was evaluated with and without the high-speed corner. Flow surveys of pressure and flow angle were taken for both the corners and the vanes to determine their respective losses. The two-dimensional vane losses were low; however, the overall corner losses were higher because three-dimensional flow was generated by the complex geometry resulting from the turning vanes intersecting the end wall. The three-dimensional effects were especially pronounced in the outer region of the circular corner
Experimental Evaluation of Turning Vane Designs for High-speed and Coupled Fan-drive Corners of 0.1-scale Model of NASA Lewis Research Center's Proposed Altitude Wind Tunnel
Two turning vane designs were experimentally evaluated for the fan-drive corner (corner 2) coupled to an upstream diffuser and the high-speed corner (corner 1) of the 0.1 scale model of NASA Lewis Research Center's proposed Altitude Wind Tunnel. For corner 2 both a controlled-diffusion vane design (vane A4) and a circular-arc vane design (vane B) were studied. The corner 2 total pressure loss coefficient was about 0.12 with either vane design. This was about 25 percent less loss than when corner 2 was tested alone. Although the vane A4 design has the advantage of 20 percent fewer vanes than the vane B design, its vane shape is more complex. The effects of simulated inlet flow distortion on the overall losses for corner 1 or 2 were small
Supersonic through-flow fan design
The NASA Lewis Research Center has embarked on a program to experimentally prove the concept of a supersonic through-flow fan which is to maintain supersonic velocities throughout the compression system with only weak shock-wave flow losses. The detailed design of a supersonic through-flow fan and estimated off-design performance with the use of advanced computational codes are described. A multistage compressor facility is being modified for the newly designed supersonic through-flow fan and the major aspects of this modification are briefly described
Detailed flow surveys of turning vanes designed for a 0.1-scale model of NASA Lewis Research Center's proposed altitude wind tunnel
Detailed flow surveys downstream of the corner turning vanes and downstream of the fan inlet guide vanes have been obtained in a 0.1-scale model of the NASA Lewis Research Center's proposed Altitude Wind Tunnel. Two turning vane designs were evaluated in both corners 1 and 2 (the corners between the test section and the drive fan). Vane A was a controlled-diffusion airfoil and vane B was a circular-arc airfoil. At given flows the turning vane wakes were surveyed to determine the vane pressure losses. For both corners the vane A turning vane configuration gave lower losses than the vane B configuration in the regions where the flow regime should be representative of two-dimensional flow. For both vane sets the vane loss coefficient increased rapidly near the walls
Effect of Copper Fed at Different Levels and for Different Lengths of Time to Growing-Finishing Pigs
Previous work at the South Dakota station reported in A.S. Series 71-33 has shown that pigs fed 250 parts per million (ppm) copper in the diet have an increased rate of gain with the greatest response occurring during the early growth period. Livercopper stores are elevated by feeding 250 ppm of copper. The experiment reported herein was designed to study the effectiveness of various levels of dietary copper as well as to determine the carry-over effect of copper treatments administered only during an initial 8-week treatment period. The antibiotic tylosin was included as one treatment to aid in evaluating the copper effect
A Phase-Field Model of Spiral Dendritic Growth
Domains of condensed-phase monolayers of chiral molecules exhibit a variety
of interesting nonequilibrium structures when formed via pressurization. To
model these domain patterns, we add a complex field describing the tilt degree
of freedom to an (anisotropic) complex-phase-field solidification model. The
resulting formalism allows for the inclusion of (in general, non-reflection
symmetric) interactions between the tilt, the solid-liquid interface, and the
bond orientation. Simulations demonstrate the ability of the model to exhibit
spiral dendritic growth.Comment: text plus Four postscript figure file
Chemically modified electrodes. Radiofrequency plasma polymerization of vinylferrocene on glassy carbon and platinum electrodes
Vinylferrocene can be polymerized in a radiofrequency Ar plasma to deposit
in thin, adherent films on qlassy carbon and Pt electrodes. In acetonitrile
solvent containinig tetraethylammonium perchlorate or tetrafluoroborate electrolyte,
these films exhibit electrochemical reactivity qualitatively expectable
for polyvinylferrocene films although analytical information on film composition
shows some plasma damage and some oxygen incorporation has taken place. The
relationship of observed electrochemistry to plasma reaction time and geometry
is described, Quantities of electroactive ferrocene in the prepared films ranqe
from 0.5 - 300 x 10-10 mole/cm.2 . The thinner films exhibit non-limiting
transport of electrochemical charge, while a thick film gives a diffusion controlled
response
Some recent rural radio talks
Cream stirring is important. - D.C. Mickle
Crossbreeding in pig production. - P. Beck
Salmonella infection in sheep. - I.J. Miller
Useful sprays for the home garden. A.A. Holland
Tapeworm of dogs and cats. P.B. Lewis
The poison plant and the animal. - R.D. Royce
Sire surveys to prove bulls. K. Needham
Peat as a substitute for horse manure. - L.T. Jone
Power-by-the-hour: the role of technology in reshaping business strategy at Rolls-Royce
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