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Theoretical and experimental investigation of additive drag
Get PDFThe significance of additive drag is discussed and equations for determining its approximate value are derived for annular and open-nose inlets. Charts are presented giving values of additive drag coefficient over a range of free-stream Mach numbers for open and for annular-nose inlets with conical flow at the inlet. The effects on additive drag of variable inlet-total-pressure recovery and static pressures on the centerbody are investigated and an analytical method of predicting the variation of pressure on the centerbody with mass-flow ratio is given. Experimental additive-drag values are presented for a series of 20 degree and 25 degree cone half-angle inlets and one open-nose inlet operating at free-stream Mach numbers of 1.8 and 1.6. A comparison with the theoretical values of additive drag shows excellent agreement for the open-nose inlet and moderately good agreement for the annular inlets. (author
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NACA Technical Reports
No full text"The significance of additive drag is discussed and equations for determining its approximate value are derived for annular and open-nose inlets. Charts are presented giving values of additive drag coefficient over a range of free-stream Mach numbers for open and for annular-nose inlets with conical flow at the inlet. The effects on additive drag of variable inlet-total-pressure recovery and static pressures on the centerbody are investigated and an analytical method of predicting the variation of pressure on the centerbody with mass-flow ratio is given" (p. 1)
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NACA Research Memorandums
No full text"The significance of additive drag is discussed and equations for determining its approximate value are derived. Charts are presented giving values of additive drag for open-nose inlets and for annular-nose inlets with conical flow at the inlet. The effects of variable inlet total-pressure recovery and static pressures on the center body are investigated, and an analytical method of predicting the variation of pressure on the center body with mass-flow ratio is given" (p. 1)
Theoretical and experimental investigation of additive drag
Get PDFThe significance of additive drag is discussed and equations for determining its approximate value are derived. Charts are presented giving values of additive drag for open-nose inlets and for annular-nose inlets with conical flow at the inlet. The effects of variable inlet total-pressure recovery and static pressures on the center body are investigated, and an analytical method of predicting the variation of pressure on the center body with mass-flow ratio is given. Experimental values of additive drag are compared with values predicted by the methods
Boundary Layer Measurements at Supersonic Nozzle Throats
Get PDFWall static pressure measurements and boundary layer pitot pressure surveys were made near the throat of a flexible wall supersonic wind-tunnel nozzle at three settings having throat radii of curvature from 33 to 59 inches. It is found that the longitudinal static pressure gradient at the nozzle throat calculated from one-dimensional flow theory agreed with the measured wall static pressure gradient.
The boundary-layer velocity profiles at the nozzle throat are presented and discussed. The boundary layers were turbulent and 0.046 to 0.107 inch thick. It is found that the boundary-layer momentum thickness at the nozzle throat calculated using the momentum-integral-equation and several approximations agrees with the values determined from the measured boundary layer profiles. Finally, it is noted that in spite of the different static pressure gradients, the boundary-layer velocity profiles for the different nozzle settings are similar, and it is shown analytically that this similarity is to be expected.</p
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NACA Technical Notes
No full textReport presenting a method for calculating the pressure drop of a high-speed compressible fluid in a constant-area duct under the simultaneous action of friction and heat transfer. The temperature distribution assumed in the development of the working chart can be made to closely approximate, in on one or two steps, the temperature distributions found in the cooling passages of ramjet and tail-pipe-burner combustion chambers
Chart for Simplifying Calculations of Pressure Drop of a High-Speed Compressible Fluid Under Simultaneous Action of Friction and Heat Transfer - Application to Combustion-Chamber Cooling Passages
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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