High Lift, Low Pitching Moment Airfoils

Two families of airfoil sections which can be used for helicopter/rotorcraft rotor blades or aircraft propellers of a particular shape are prepared. An airfoil of either family is one which could be produced by the combination of a camber line and a thickness distribution or a thickness distribution which is scaled from these. An airfoil of either family has a unique and improved aerodynamic performance. The airfoils of either family are intended for use as inboard sections of a helicopter rotor blade or an aircraft propeller

Effect of Blade Planform Variation on a Small-Scale Hovering Rotor

A hover test was conducted on a small-scale rotor model for three sets of tapered rotor blades and a baseline rectangular planform rotor blade. All configurations had the same airfoils, twist, and thrust-weighted solidity. The tapered blade planforms had taper initiating at 50, 75, and 94 percent of the blade radius with a taper ratio of 3 to 1 for each blade set. The experiment was conducted for a range of thrust coefficients, and the data were compared to the predictions of three hover analysis methods. The data show the 94 percent tapered blade was slightly more efficient at the higher rotor thrust levels. The other tapered planform rotors did not show the expected improvement over the baseline rotor, and all configurations had similar performance for low thrust coefficients. None of the analysis methods correlated well with the experimental data

Rotor blade aerodynamic design

Aerodynamic performance aspects of rotor blade design are presented. Design considerations, aerodynamic constraints and design variables are described

Intersection of Patent Infringement and Antitrust Liability in Abbreviated New Drug Application Litigation, The

A battle has been raging, over the past ten years, regarding the competing interests of patent protection and antitrust prohibitions in the specialized area of law concerned with patented drugs regulated by the Food and Drug Administration ( FDA ).\u27 The contestants are the Federal Trade Commission ( FTC ) and parties to Abbreviated New Drug Application (ANDA) litigation, which are a branded drug company and a generic challenger

An application of active surface heating for augmenting lift and reducing drag of an airfoil

Application of active control to separated flow on the RC(6)-08 airfoil at high angle of attack by localized surface heating is numerically simulated by integrating the compressible 2-D nonlinear Navier-Stokes equation solver. Active control is simulated by local modification of the temperature boundary condition over a narrow strip of the upper surface of the airfoil. Both mean and perturbed profiles are favorably altered when excited with the same natural frequency of the shear layer by moderate surface heating for both laminar and turbulent separation. The shear layer is found to be very sensitive to localized surface heating in the vicinity of the separation point. The excitation field at the surface sufficiently altered both the local as well as the global circulation to cause a significant increase in lift and reduction in drag

Aerodynamic characteristics of two rotorcraft airfoils designed for application to the inboard region of a main rotor blade

A wind tunnel investigation was conducted to determine the 2-D aerodynamic characteristics of two new rotorcraft airfoils designed especially for application to the inboard region of a helicopter main rotor blade. The two new airfoils, the RC(4)-10 and RC(5)-10, and a baseline airfoil, the VR-7, were all studied in the Langley Transonic Tunnel at Mach nos. from about 0.34 to 0.84 and at Reynolds nos. from about 4.7 to 9.3 x 10 (exp 6). The VR-7 airfoil had a trailing edge tab which is deflected upwards 4.6 degs. In addition, the RC(4)-10 airfoil was studied in the Langley Low Turbulence Pressure Tunnel at Mach nos. from 0.10 to 0.44 and at Reynolds nos. from 1.4 to 5.4 x 10 (exp 6) respectively. Some comparisons were made of the experimental data for the new airfoils and the predictions of two different theories. The results of this study indicates that both of the new airfoils offer advantages over the baseline airfoil. These advantages are discussed

Two-dimensional aerodynamic characteristics of the OLS/TAAT airfoil

Two flight tests have been conducted that obtained extension pressure data on a modified AH-1G rotor system. These two tests, the Operational Loads Survey (OLS) and the Tip Aerodynamics and Acoustics Test (TAAT) used the same rotor set. In the analysis of these data bases, accurate 2-D airfoil data is invaluable, for not only does it allow comparison studies between 2- and 3-D flow, but also provides accurate tables of the airfoil characteristics for use in comprehensive rotorcraft analysis codes. To provide this 2-D data base, a model of the OLS/TAAT airfoil was tested over a Reynolds number range from 3 x 10 to the 6th to 7 x 10 to the 7th and between Mach numbers of 0.34 to 0.88 in the NASA Langley Research Center's 6- by 28-Inch Transonic Tunnel. The 2-D airfoil data is presented as chordwise pressure coefficient plots, as well as lift, drag, and pitching moment coefficient plots and tables

BIOTECHNOLOGY PATENT LAW TOP TEN OF 2021. EXPERIMENTATION, BLAZE MARKS, AND UNSPECIFIED RANGES

Biotechnology has never demonstrated its benefits to society more than in 2021. The SARS-CoV-2 virus that caused the CoVID-19 pandemic met a formidable opponent in mRNA vaccines developed and supplied by Moderna and Pfizer/BioNTech. These vaccines are claimed in myriad – not Myriad – patents and patent applications, many of which are destined to be litigated over the coming years, not least inspired by the many billions of dollars that have been, and will continue to be, earned by their owners. While the world waits for this storm of patent litigation, federal courts continue to be busy with ownership, licensing, validity, and infringement disputes arising from other biotechnologies, including, perhaps, up-and-coming CAR-T therapies. For the fourth year in a row (of what has become a tradition), we discuss, in this article, the ten most consequential, important, and interesting court decisions involving biotechnology patents. Our top ten decisions may not be the same as top tens compiled by others. However, to quote an expression commonly heard in courts hearing patent cases, à chacun son goût. Patent decisions delivered during 2021 tackled a diverse group of doctrinal issues. As discussed in the article, these ranged from how much experimentation is to be considered undue à la In re Wands, to what level of detail of disclosure is sufficient to satisfy the ever- written description requirement, to which types of behavior may rise to the level of inducement to infringe, not to mention assignor estoppel. Patent litigations filed in federal district court rose to 3,798, a number not seen since 2016. In contrast, the 1,333 patent actions filed with the Patent Trial and Appeal Board (“PTAB“) represented a substantial decline from 2020. In short, despite the challenges of the CoVID- 19 pandemic, patent litigation in 2021 evinced considerable vim and vigor. Described and analyzed in this article are the vimmiest and most vigorous of 2021 patent decisions