The innovation is a computer program which can be used to design two-dimensional or axisymmetric nozzles having uniform or non-uniform (Mach number and/or flow angle) supersonic inflow. If possible, the computer program generates a nozzle contour which produces supersonic, shock-free, uniform flow at the nozzle exit. (Certain non-uniform inflow conditions may create a shockwave which violates the potential flow assumption, stopping the program.) The program also give the user control over the geometry at inflow and in the expansion region of the nozzle.

The software will load in image collections from Google Earth Engine from different sensors (Landsat 5, 7, and 8, Sentinel 2a, 2b) and the code will identify pixels meeting certain criteria as snow using two snow indices (Normalized Difference Snow Index (NDSI) and the Saito S3 Snow Index. Then the area of snow can be calculated for a region or for an individual watershed. Then a chart can be generated which would create a visual that shows the change in area covered by snow across images as a percentage of the whole area. As the sky islands stretch across much of Southeastern Arizona, the software also eliminates the need to download multiple images from differing rows/paths.

abaverify is a collection of Python scripts that is used for testing and verifying the behavior of user subroutines for the commercial finite element code Abaqus.

This innovation is a thermal processing methodology for retaining the fine-grained structure in aluminum alloys subjected to solid state welding and subsequent forming processes.

Heat treatment of the deformed welds is desirable in order to restore the properties of the alloy negatively affected in the weld region. In these alloys, abnormal grain growth frequently occurs in friction stir welds during solution heat treatment, and is known to degrade key materials properties, such as strength, ductility and toughness. The innovation of inserting an intermediate annealing step covered here reduces abnormal grain growth during post-welding heat treatment, thereby allowing optimum mechanical properties. This is important where Al-Li alloys (and other heat treatable alloys) are friction stir welded followed by deformation processing and high performance, high reliability structural components are required for aerospace vehicles.

This invention uses microphones that are "self-calibrated" using electrical actuation, and feedback control that "self-matches" the frequency response of each microphone in the array based on user specifications. NASA Langley and Michigan State University have developed and tested a microphone prototype using a thin polyvinyledinefluoride (PVDF) film membrane, which allows for actuation in a feedback scheme. The feedback actively modifies such sensor parameters as membrane stiffness, resonant frequency, damping, and DC attenuation. A fiber-optic sensor was used to detect displacement of the membrane's center caused by acoustic pressure. The feedback response was verified as closely matching what was predicted.

The Acoustic Propagation and Emulation Toolset (APET) is a framework code uniting several acoustic methodologies for the propagation and measurement of source noise audibility at farfield observers, accounting for the effects of the atmosphere, weather, terrain, and spherical spreading. Currently, APET consists of a modified version of the Rotorcraft Noise Model (RNM, Version 7) coupled with the newly developed Spectral Attenuation Method (SAM) that contains the Ray Tracing Program (RTP) and two versions of a Greens Function Parabolic Equation (GFPE) code. A third component of APET is an audibility prediction scheme based on the work of Abrahamson, initially called ICHIN (I Can Hear It Now) and further developed by Wyle Labs as AUDIB.

An active pylon noise control system for an aircraft includes a pylon structure connecting an engine system with an airframe surface of the aircraft and having at least one aperture to supply a gas or fluid therethrough, an intake portion attached to the pylon structure to intake a gas or fluid, a regulator connected with the intake portion via a plurality of pipes, to regulate a pressure of the gas or fluid, a plenum chamber formed within the pylon structure and connected with the regulator, and configured to receive the gas or fluid as regulated by the regulator, and a plurality of injectors in communication with the plenum chamber to actively inject the gas or fluid through the plurality of apertures of the pylon structure.

Acoustical studies of atmospheric events like convective storms, shear-induced turbulence, acoustic gravity waves, microbursts, hurricanes, and clear air turbulence over the last forty-five years have established that these events are strong emitters of infrasound (sound at frequencies below 20 Hz). Over the years, NASA Langley has designed and developed a portable infrasonic detection system which can be used to make useful infrasound measurements at a location where it was not possible previously. The system comprises an electret condenser microphone, and a small, compact windscreen. The system has been modified to be used in the air, underground, as well as underwater (to determine man-made and precursor to tsunami). The system also features a data acquisition system that permits real-time detection, bearing, and signature of a low frequency source. However, to determine bearing of the received signals, the microphones are to be arranged as an equilateral triangle with a certain microphone spacing. The spacing depends upon location of the microphone array. For a ground-based array, the microphone spacing of 100 feet (30.48m) is desired to determine time delay for signals arriving at each microphone location. The microphone spacing depends upon speed of sound through the array medium. For underwater array, the spacing between microphones would be around 1500 feet. The data acquisition system provides data output in the infrasonic bandwidth which is then analyzed using an adaptive algorithm (least-mean-squares time-delay-estimation) using modern computational power to locate source by plotting source location hyperbolas on-line. A smaller array size reduces the time resolution resulting in strong signal coherence. The innovation approach is to exploit modern signal processing methods, i.e. adaptive filtering, where computer is trained on-line to recognize features of the event to be detected. Modern computational capability permits the adaptive algorithm (least-mean-squares time-delay estimation or LMSTDE) which is vastly more powerful algorithm. This system has better resolution able to determine direction with arrived signals within five-degree accuracy.