FREE-FLIGHT INVESTIGATION AT TRANSONIC SPEEDS OF THE STABILITY CHARACTERISTICS OF A TAILLESS MISSILE CONFIGURATION HAVING A 45 DEG SWEPTBACK WING OF ASPECT RATIO 4

Free flight test of tailless missile configuration with 45-deg sweptback wing of aspect ratio 4 - stability at transonic speed

A primer on global internal tide and internal gravity wave continuum modeling in HYCOM and MITgcm

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146536/1/bookchapter_2018_arbicetal.pdfDescription of bookchapter_2018_arbicetal.pdf : Main articl

Transonic Free-Flight Investigation of the Longitudinal Aerodynamic Characteristics of a 1/10-Scale Steel-Wing Model of the Northrop MX-775A Missile with Leading-Edge Extensions, Inboard Trailing-Edge Flaps, and a Speed Brake on the Vertical Tail

Results are presented of a free-flight investigation between Mach numbers of 0.7 to 1.3 and Reynolds numbers of 3.1 x 10(exp 6) to 7.0 x 10(exp 6) to determine the longitudinal aerodynamic characteristics of the Northrop MX-775A missile. This missile has a weng, body, and vertical tail, but has no horizontal tail. The basic wing plan form has an aspect ratio of 5.5, 45 deg of sweepback of the 0.406 streamwise chord line, and a taper ratio of 0.4. A 1/10-scale steel-wing model of the missile was flown with modifications to the basic wing plan form consisting of leading-edge chord-extensions deflected 7 deg downward together with the forward 15 percent of the wing chord, and inboard trailing-edge flaps deflected 5 deg downward. In addition, the model had a static-pressure tube mounted at the tip of the vertical tail for position-error measurements and had a speed brake also mounted on the vertical tail to trim the model to positive lift coefficients and to permit determination of the trim and drag effectiveness of the brake. The data are uncorrected for the effects of wing elasticity, but experimental wing influence coefficients are presented

Geostrophic turbulence in the frequency-wavenumber domain: Eddy-driven low-frequency variability

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146535/1/jpo_2014_frequencywavenumbercascades.pdfDescription of jpo_2014_frequencywavenumbercascades.pdf : Main articl

CONNECTING PROCESS MODELS OF TOPOGRAPHIC WAVE DRAG TO GLOBAL EDDYING GENERAL CIRCULATION MODELS

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152448/1/oceanography_2019_leewavedrag.pdfDescription of oceanography_2019_leewavedrag.pdf : Main articl

Can We Infer Ocean Dynamics from Altimeter Wavenumber Spectra?

The wavenumber spectra of sea surface height (SSH) and kinetic energy (KE) have been used to infer the dynamics of the ocean. When quasi-geostrophic dynamics (QG) or surface quasi-geostrophic (SQG) turbulence dominate and an inertial subrange exists, a steep SSH wavenumber spectrum is expected with k-5 for QG turbulence and a flatter k-11/3 for SQG turbulence. However, inspection of the spectral slopes in the mesoscale band of 70 to 250 km shows that the altimeter wavenumber slopes typically are much flatter than the QG or SQG predictions over most of the ocean. Comparison of the altimeter wavenumber spectra with the spectra estimated from the output of an eddy resolving global ocean circulation model (the Hybrid Coordinate Ocean Model, HYCOM, at 1/25 resolution), which is forced by high frequency winds and includes the astronomical forcing of the sun and the moon, suggests that the flatter slopes of the altimeter may arise from three possible sources, the presence of internal waves, the lack of an inertial subrange in the 70 to 250 km band and noise or submesoscales at small scales. When the wavenumber spectra of SSH and KE are estimated near the internal tide generating regions, the resulting spectra are much flatter than the expectations of QG or SQG theory. If the height and velocity variability are separated into low frequency (periods greater than 2 days) and high frequency (periods less than a day), then a different pattern emerges with a relatively flat wavenumber spectrum at high frequency and a steeper wavenumber spectrum at low frequency. The stationary internal tides can be removed from the altimeter spectrum, which steepens the spectral slopes in the energetic internal wave regions. Away from generating regions where the internal wave

Summary of Rocket-Model Tests at Zero Lift of the Northrop MX-775B Missile Configuration from Mach Numbers of 0.9 to 1.8

Flight tests were conducted between Mach numbers of 0.9 and 1.8 over a Reynolds number range of 9(exp 6) to 30(exp 6) to determine the zero-lift drag and some rolling-effectiveness characteristics of the Northrop MX -775B missile with small and large body. The MX-775B is a proposed long range, supersonic, ground-to-ground missile having an arrow wing with 67.5 degree leading-edge sweep, 15 deg trailing-edge sweep, and a modified NACA 0004 airfoil section. The configuration has no horizontal tail but has wing trailing-edge elevons which serve a dual purpose as elevators and ailerons. The ratio of body frontal area to wing plan-form area is 0.0127 for the small-body configuration and 0.0330 for the large-body configuration. Five 1/4-scale models were flown permitting determination of the drag coefficient for the basic small-body configuration, the incremental drag due to the large body, the incremental drag resulting from a blunt wing trailing edge, the wing-plus-interference drag, and some rolling-effectiveness data. Results indicated that the MX-775B has low supersonic zero-lift drag, the maximum zero-lift drag coefficients being respectively 0.0125 and 0.0155 at a Mach number of M = 1803 for the small- and large-body configurations. The effect of a blunt wing trailing edge, obtained by cutting off 10 percent of the wing chord, was to increase the zero-lift drag by 13 to 21 percent. Wing-plus-interference drag accounted for 78 percent of the total drag at M = 0.9 and 70 percent at M = 195 for the small-body configuration. The ailerons produced positive rolling effectiveness for the wing stiffness of the test models and the dynamic pressures of the test

Efficient Gradient-based Optimization for Reconstructing Binary Images in Applications to Electrical Impedance Tomography

A novel and highly efficient computational framework for reconstructing binary-type images suitable for models of various complexity seen in diverse biomedical applications is developed and validated. Efficiency in computational speed and accuracy is achieved by combining the advantages of recently developed optimization methods that use sample solutions with customized geometry and multiscale control space reduction, all paired with gradient-based techniques. The control space is effectively reduced based on the geometry of the samples and their individual contributions. The entire 3-step computational procedure has an easy-to-follow design due to a nominal number of tuning parameters making the approach simple for practical implementation in various settings. Fairly straightforward methods for computing gradients make the framework compatible with any optimization software, including black-box ones. The performance of the complete computational framework is tested in applications to 2D inverse problems of cancer detection by electrical impedance tomography (EIT) using data from models generated synthetically and obtained from medical images showing the natural development of cancerous regions of various sizes and shapes. The results demonstrate the superior performance of the new method and its high potential for improving the overall quality of the EIT-based procedures.Comment: 26 pages, 10 figures. arXiv admin note: text overlap with arXiv:2011.01790, arXiv:2211.0622

Large-Scale Flight Measurements of Zero-Lift Drag at Mach Numbers from 0.90 to 1.95 of 1/14-Scale Model of the Northrop MX-775B Pilotless Aircraft with Small Body

A flight test was made a t high subsonic, transonic, and supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of a 1/14-scale model of the Northrop MX-775B pilotless aircraft with small small body. The triangular wing of the model had 67.5 deg leading-edge sweep and 15 deg. trailing-edge sweep, The wing airfoil sections were modified NACA 0004 sections. The drag coefficient based on total wing area was 0.0107 at Mach number 1.60. At transonic speeds the maximum drag coefficient was 0.0125. The force-break Mach number was 0,98