*TEMPERATURE GRADIENTS - Storming Media

FASST Soil Moisture, Soil Temperature: Original Versus New

01-Apr-2008

36 pages

Authors: Susan Frankenstein; ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB

The full text of this report is available for sale.

This paper discusses only the differences between the original version of FASST (Frankenstein and Koenig 2004a, 2004b) and the new version. This report is intended as a supplement to the original model documentation. In its original incarnation, energy and mass transport associated with water vapor in the soil matrix were ignored. The author added these so that model usage could be expanded to include biological investigations yet still retain its ...

Characteristics of Thermal Finestructure in the Southern Yellow Sea and the East China Sea from Airborne Expendable Bathythermograph Measurements

01-Jan-2008

60 pages

Authors: Sunghyea Park; Peter C Chu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY

Four surveys of airborne expendable bathythermograph with horizontal spacing of about 35 km and vertical spacing of 1 m extending from the surface down to 400 m deep are used to analyze thermal finestructures and their seasonality in frontal zones of the southern Yellow Sea and the East China Sea. Finestructure characteristics are different not only among fronts but also along the same front, implying different mixing mechanisms. Summer thermocline ...

Thermal Fronts and Cross-Frontal Heat Flux in the Southern Yellow Sea and the East China Sea

2008

Authors: Sunghyea Park; Peter C. Chu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY

The full text of this report is not available and therefore is not for sale. This information is provided for reference purposes only.

Synoptic features in/around thermal fronts and cross-frontal heat fluxes in the southern Yellow Sea and East China Sea (YES) were examined using the data collected from four airborne expendable bathythermograph surveys with horizontal ~35 km and vertical 1 m (from the surface to 400 m deep) spacings. Since the fronts are strongly affected by YES current system, the synoptic thermal features in/around them represent the interaction of currents with surrounding ...

Freezing Fog Formation in a Supercooled Boundary Layer: Solving the Winter Fog Forecasting Challenge for Elmendorf Air Force Base, Alaska

MAR 2007

105 pages

Authors: Bradley J. Harbaugh; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

We have examined four complex freezing fog events at Elmendorf Air Force Base, Alaska, to determine the root cause of the fog. These events have drastically impacted operations in the region for years, and are still a mystery to forecasters. The primary goal was to provide a detailed analysis of conditions within the boundary layer that contributed to freezing fog formation within the supercooled liquid water boundary layer. The data ...

Analytical Model for Sensor Placement on Microprocessors

2005

5 pages

Authors: Kyeong-Jae Lee; Kevin Skadron; Wei Huang; VIRGINIA UNIV CHARLOTTESVILLE

Thermal management in microprocessors has become a major design challenge in recent years. Thermal monitoring through hardware sensors is important, and these sensors must be carefully placed on the chip to account for thermal gradients. In this paper, we present an analytical model that describes the maximum temperature differential between a hot spot and a region of interest based on their distance and processor packaging information. We also use a ...

Thermal Gradient Data Acquisition System Documentation

DEC 2004

29 pages

Authors: Larry D. Walker; Scott B. Robinson; Lisa Leon; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION

This report describes a data acquisition system developed to obtain position and temperature measurements from a mouse thermal gradient following heat exposure or any other thermoregulatory event that can be recorded in mice. Since acceptable commercial systems are not available, this system was custom- built to acquire data using National Instruments' versatile hardware components and LabVIEW 7.0 Express Developmental Software. General requirements for this system are that it be highly ...

Thermal and Electrochemical Models for Batteries During High Rates of Discharge

15 AUG 2004

232 pages

Authors: John W. Van Zee; SOUTH CAROLINA UNIV COLUMBIA OFFICE OFSPONSORED PROGRAMS

The first of the three pans of this work documents the effort toward the original objective of the grant: understanding how commercial software could be modified to understand the three dimensional thermal and electrochemical gradients in a silver/zinc battery during high rates of discharge. This objective had broad applications for accelerated design of new batteries if we could use the mathematical solvers in commercial software packages because these software packages ...

An Experimental Investigation into the Temperature Profile of a Compliant Foil Air Bearing

MAY 2004

20 pages

Authors: Kevin Radil; Michelle Zeszotek; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH GLENN RESEARCH CENTER

A series of tests was performed to determine the internal temperature profile in a compliant bump-type foil journal air bearing operating at room temperature under various speeds and load conditions. The temperature profile was collected by instrumenting a foil bearing with nine, type K thermocouples arranged in the center and along the bearing's edges in order to measure local temperatures and estimate thermal gradients in the axial and circumferential directions. ...

The Recent Expansion of Pluto's Atmosphere

10 JUL 2003

5 pages

Authors: J. L. Elliot; A. Ates; B. A. Babcock; A. S. Bosh; M. W. Buie; NAVAL OBSERVATORY FLAGSTAFF AZ

Stellar occultations -- the passing of a relatively nearby body in front of a background star -- can be used to probe the atmosphere of the closer body with a spatial resolution of a few kilometers. Such observations can yield the scale height, temperature profile, and other information about the structure of the occulting atmosphere. Occultation data acquired for Pluto's atmosphere in 1988 revealed a nearly isothermal atmosphere(sup 2) above ...

Further Investigations of a Mesospheric Inversion Layer Observed in the ALOHA-93 Campaign

15 OCT 2002

9 pages

Authors: Tai-Yin Huang; Michael P. Hickey; Tai-Fu Tuan; E. M. Dewan; R. H. Picard; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE

Temperature and wind data obtained from a Na wind/temperature lidar operated by the University of Illinois group during the Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) Campaign, previously analyzed by Huang et al. 1998 using an isothermal Brunt-Vaisala frequency, have been reexamined to include temperature gradients in the calculation of the Richardson number. In the previous analysis using the isothermal Brunt-Vaisala frequency the existence of convective instability could ...

A Numerical Study of the Forcing Mechanisms of the Leeuwin Current System

SEP 2002

117 pages

Authors: Richard A. Kennedy Jr.; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

To investigate the role of wind forcing, bottom topography and thermohaline gradients in the Leeuwin Current System (LCS) , several experiments are conducted with a sigma coordinate primitive equation model on a beta- plane. Results show that the LCS is an anomalous eastern boundary current (EBC) that generates a coastal poleward current, an equatorward undercurrent, and highly energetic mesoscale features such as meanders and eddies. Thermohaline gradient effects were shown ...

A Fine Resolution Model of the Leeuwin Current System

DEC 2001

76 pages

Authors: Scott Boedeker; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

To investigate the role of wind forcing, bottom topography and thermohaline gradients on classical as well as unique features of the Leeuwin Current system (LCS) five experiments are conducted with a sigma coordinate, primitive equation model on a beta-plane. The first experiment, which investigates the pressure gradient force error, shows that velocity errors, inherent in three dimensional sigma coordinate models, can be successfully reduced from 100 cm/s to 1 cm/s ...

Finite Element Modeling of Cooling Coil Effects in Mass Concrete Systems

AUG 2001

121 pages

Authors: Robert M. Strigel; WASHINGTON UNIV ST LOUIS MO

Over the past decade, the U.S. Army Corps of Engineers has developed and implemented the use of NISA (nonlinear, incremental 1 analysis) procedures to predict the effect of thermal loads due to the heat of hydration of cement in massive concrete structures during construction. To date, the commercial program ABAQUS has been used to perform a majority of the NISA's due to its versatility. Recently, a need to develop a ...

One-Way Flow of a Rarefied Gas Induced in a Circular Pipe with a Periodic Temperature Distribution

09 JUL 2000

9 pages

Authors: K. Aoki; Y. Sone; S. Takata; K. Takahashi; G. A. Bird; KYOTO UNIV (JAPAN) DEPT OF AERONAUTICSAND ASTRONAUTICS

The steady behavior of a rarefied gas in a circular pipe with a saw- like temperature distribution increasing and decreasing periodically in the direction of the pipe axis is investigated numerically by means of the direct simulation Monte Carlo method. It is shown that a steady one-way flow is induced in the pipe without the help of a pressure gradient for a wide range of the Knudsen number when a ...

Thermophoresis of Axially Symmetric Bodies

09 JUL 2000

9 pages

Authors: Karl I. Borg; Lars H. Soederholm; ROYAL INST OF TECH STOCKHOLM (SWEDEN) DEPT OF MECHANICS

Thermophoresis of axially symmetric bodies is investigated to first order in the Knudsen-number, Kn. The study is made in the limit where the typical length of the immersed body is small compared to the mean free path. It is shown that in this case, in contrast to what is the case for spherical bodies, the arising thermal force on the body is not in general antiparallel to the temperature gradient. ...

Effects of Thermohaline Gradients and the Columbia River Plume on the California Current System

MAR 2000

108 pages

Authors: Frank M. Schenk; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

To study the combined effects of thermohaline gradients and the Columbia River plume on the ocean circulation of the California Current System (CCS), results from three numerical experiments of increasing complexity are examined. In all three experiments, seasonal climatological winds are used to force the model. In the first experiment, the effects of seasonal thermohaline gradients along the western boundary are evaluated. In the second ...

0N Mechanical Properties of Materials by Thermal Wave Imaging

24 JUL 95

25 pages

Authors: R. L. Thomas; L. D. Favro; P. K. Kuo; WAYNE STATE UNIV DETROIT MI INST FOR MANUFACTURING RESEARCH

Research was carried out to: (1) Utilize WSU fast imaging techniques to study the temperature distribution in the vicinity of the crack tips of propagating cracks in polymer composites; (2) Utilize Wayne State University's thermal wave imaging techniques for studying adhesive bond strength; and (3) Exploit the concept of vector lock-in video thermal wave imaging for mechanical and thermal response of semiconductors. Key results included: (1) a Physical Review letter: ...

Detecting Temperature Anomalies in Towed Sensor System Data

14 JUL 95

33 pages

Authors: Richard K. Myrick; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS

Internal turbulent mixing events, internal gravity waves and encounters with fronts in the oceans are usually accompanied by large variances of water temperature and conductivity, relative to the average background state. Long chains of densely spaced sensors are towed through the water to detect and quantify these relatively rare, random events. The time and locations of the events cannot be predicted, so these sensors must collect data continuously in order ...

Transport of Tracer Br in Frozen Morin Clay in Response to Temperature Gradients

FEB 95

17 pages

Authors: Yoshisuke Nakano; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

The movement of water and Br was measured in unsaturated and partially frozen soil columns subjected to linear temperature fields. Both water and Br moved from the warmer to cooler parts in the columns. The data were analyzed under the assumption that Br is confined to unfrozen water. It was found that the negative adsorption of Br by clay surfaces plays a significant role in the transport of Br in ...

Thermoacoustic sound Generator.

29 NOV 1994

Authors: Thomas B. Gabrielson; DEPARTMENT OF THE NAVY WASHINGTON DC

A submersible acoustic generator for projection of sound waves into a body of water comprises a tubular resonator, open at its lower end and closed at its upper end, and having a multiple-plate thermoacoustic stack located near the upper end between a pair of heat ex changers which set up a temperature gradient in the stack The upper heat exchanger is heated by a chemical fuel, and the lower heat ...

Real Time System for Practical Acoustic Monitoring of Global Ocean Temperature

04 NOV 94

Authors: John L. Spiesberger; Daniel E. Frye; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

The acoustic multipaths from the Kaneohe source have been identified at one SOSUS station using a ray tracing algorithm called ZRAY. This is the furthest, 4000 km, that ray theory has been successfully used to understand acoustic propagation in the ocean. This further validates that acoustic thermometry is valid at basin-scales and that changes in the travel time from the Kaneohe source are not due to changes in the multipaths. ...

Models to Estimate High Frequency Acoustic Scattering Due to Thermal Fine- and Micro-Structure of the Ocean

JUN 94

53 pages

Authors: R. A. Thuraisingham; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION MELBOURNE (AUSTRALIA)

Existing models to obtain intensity and phase changes of sound due to thermal fluctuations in the ocean, such as that developed by Chernov, are limited in their application. They are valid only for an isotropic medium and where the range is much greater than the correlation distance of the fluctuations. Extensions to short range and for an anisotropic medium are described here, both for the stochastic wave and ray models. ...

Calculations via Successive Approximations of Stress and Strain Distribution in Thick-Walled Concentric Tubes Due to a Radial Temperature Gradient

MAR 94

24 pages

Authors: Boaz Avitzur; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS

When thick-walled tubes are subjected to radial temperature gradients, cooler portions of the tubes impose constraints on the thermal expansion of hotter segments. (For example, in an internally heated tube, outer portions of the tube contain the expansion of the inner layer.) Constraint of the thermal expansion results in triaxial stress and strain distributions. A sequence of successive approximations has been used to calculate such stress and strain fields, while ...

Global Acoustic Mapping of Ocean Temperatures (GAMOUT)

DEC 93

Authors: WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Global Acoustic Mapping of Ocean Temperatures (GAMOT)

15 OCT 93

Authors: John L. Spiesberger; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Work continues on all GAMOT Tasks as described in ARPA Grant No: MDA972-93-1-0004 and remains on schedule with the exception of Tasks C and D. Task C work is behind schedule and there will be a delay in the initial deployment of the operational SSARs of approximately six weeks. Task D, the autonomous mooring, is behind schedule and the total delay cannot be calculated until the impact of the increased ...

On the Temperature Distribution Near a Cold Surface

OCT 93

29 pages

Authors: Yin-Chao Yen; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

Temperature profiles were taken during the 1991-92 season at an experimental site on CRREL's grounds; however, they were rather limited because of the unusual lack of snowfall and the location of the site, which was small and had elevated sides (especially in the direction of the prevailing wind). Nevertheless, some unusual features have been observed for the first time. The profiles show the existence of a double-reversal in temperature structure ...

A Correlation of Welding Solidification Parameters to Weld Macrostructure

18 JUN 92

93 pages

Authors: Francis G. Novak; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

A 3-D finite difference model simulating single pass autogenous welds was used to predict the temperature fields in HY-80 steel arc weldments at various powers and torch velocities. From the predicted temperature field, two important solidification parameters were calculated at the solid-liquid interface: temperature gradients and crystal growth velocities. These were correlated with the macrostructures observed in actual weldments. For purposes of model validation, the predicted and actual fusion zone ...

Thermal Effects in a Coated Medium (with a Cavity) Due to Friction Heating by a Passing Asperity

Authors: T. Y. Chen; F. D. Ju; NEW MEXICO UNIV ALBUQUERQUE

The present paper expounds the effect of a near-surface cavity, when the solid surface is subjected to the Coulomb frictional loading of an asperity moving at moderately high speed. The medium under consideration is represented by a solid-half space which is coated with a thin layer of solid wear coating. The cavity is assumed to be rectangular in cross section. The temperature field and its gradient in the vicinity of ...

Front Surface Pyrometer

08 MAR 85

Authors: Marvin M. Hoffman; LOS ALAMOS TECHNICAL ASSOCIATES INC NM

Principal users of the Tri-Service Thermal Flash Test Facility (TFTF) were surveyed to determine their perceived need for noncontact front surface temperature measurements on specimens being tested at the facility. Performance specifications and operational capabilities which define a radiation pyrometer system satisfactory for use at TFTF were developed from the results of this survey. All of the principal specifications were satisfied by a long waveband infrared (8-11.5 micrometer) pyrometer, which ...

Fine Line Electromigration. The Effect of Crossed Thermal Gradients

SEP 1983

Authors: P. G. Brusius; HONEYWELL INC PLYMOUTH MN SOLID STATE ELECTRONICS DIV

Electromigration is the phenomenon where current flow in conductors causes a momentum exchange which can, under certain conditions, result in mass transport in the conductor. Conducting material accumulates in some places on a line; voids are also created. In integrated circuits, this mechanism manifests itself in the form of high resistance lines, open circuits and/or whisker growth, which can lead to failures. Screening for the defects which cause electromigration is ...

Finestructure, Fronts and Currents in the Pacific Marginal Sea-Ice Zone - MIZPAC 77.

JUN 1978

Authors: Gordon Patrick Graham; Robert G. Paquette; Robert H. Bourke; NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Sharp vertical temperature fronts and complex temperature inversions observed in the Chukchi Sea during MIZPAC 77 were investigated in a further effort to define the mechanisms for the formation of finestructure. An association was found between the upper level current directions inferred from the gross ice edge recession rates and the occurrence of fronts and finestructure. Currents with a strong directional component normal to the ice edge were associated with ...

The Effect of Spanwise Wall Temperature Gradients on Nominally Two-Dimensional Laminar Boundary Layers,

JUN 1977

Authors: C. von Kerczek; DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD SHIP PERFORMANCE DEPT

It is argued that spanwise temperature gradients in wall heating do not affect the boundary layer crossflow to first order if the length scale of the spanwise temperature variation is much greater than the boundary layer thickness. Implications for linear instability theory and transition are discussed for flow about two-dimensional or axisymmetric bodies. (Author)

Physical Characteristics of Ocean Fronts and Eddies in the North Atlantic.

MAR 1977

Authors: R. W. James; R. E. Cheney; NAVAL OCEANOGRAPHIC OFFICE WASHINGTON D C

Ocean fronts and eddies are defined, described and typical locations given. Their formation, surface and vertical characteristics, variability, and operational system display are discussed. How to analyze and map fronts is described. (Author)

Synoptic Observations of the Oceanic Frontal System East of Japan.

FEB 1977

Authors: Robert E. Cheney; NAVAL OCEANOGRAPHIC OFFICE WASHINGTON D C

Seven flights were made east of Japan in October 1976. The Kuroshio and Oyashio fronts and nine eddies generated by them were studied from continuous measurements of surface temperature by airborne radiation thermometer. AXBT's, XBT's and STD's provided subsurface temperature profiles. (Author)

Basic Concepts of Electro- and Thermomigration; Driving Forces.

1977

Authors: Richard S. Sorbello; WISCONSIN UNIV-MILWAUKEE DEPT OF PHYSICS

The current theoretical situation in electro- and thermomigration is reviewed. The physical basis underlying the driving force concept is discussed. A new linear-response expression is given for the electron-scattering contribution in thermomigration. The phonon-scattering contribution to thermomigration is also discussed. (Author)

Finite Difference Treatment of Transient Temperature Distribution in an Insulated Pipe,

OCT 1976

Authors: John E. Brook; NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

This report discusses a Crank-Nicolson type of finite difference formulation for the problem of transient temperature distribution in a uniform cylindrical pipe with external insulation and containing a fluid for which temperature, pressure, and flow rate are given as functions of time. All material properties are assumed to depend on temperature. Discussion is also given of a digital computer program which implements this formulation. This implementation incorporates properties of superheated ...

An Optimization Study of a Low Thermal Potential Power System.

SEP 1976

Authors: J. R. Buckingham; W. M. Raike; M. D. Kelleher; NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

A power generating system using the low thermal potential available from the vertical temperature distribution of the ocean is analyzed as a combined engineering and economic mathematical model. The model is optimized for minimum capital cost employing a sequential unconstrained minimization algorithm. Examples of the kinds of engineering and cost information available from the model are presented. (Author)

A Note on Sound Ray Tracing Through a Gulf Stream Eddy in the Sargasso Sea.

MAR 1974

Authors: W. Gemmill; E. Khedouri; NAVAL OCEANOGRAPHIC OFFICE WASHINGTON D C

Demonstrates the effects of a cold Gulf Stream eddy on convergence mode sound propagation. The eddy refracts sound rays into the deep sound channel and destroys cyclic convergence zones. (Author)

Oceanic Frontal Analysis.

11 OCT 1972

Authors: Alvan Fisher Jr; NAVAL OCEANOGRAPHIC OFFICE WASHINGTON D C

A method is given for analysis of thermal structure based on identification of water masses and localization of oceanic fronts. This type of analysis is an improvement over isotherm analysis, both in objectivity and display. (Author)

Thermal Variations in Millstone Quarry.

06 JAN 1967

Authors: Lloyd C. Huff; NAVY UNDERWATER SOUND LAB NEW LONDON CONN

This report is a first attempt at rationalizing the time variations of the vertical thermal profile with existing theories on thermal mixing in the oceans. Application of present theories on thermal mixing require evaluating various physical constants. This report deals with the time and space variations of one of those physical constants - the vertical kinematic thermal eddy diffusitivity, K sub z.

A DETERMINATION OF THE TEMPERATURE FIELD AND THE HEAT LOSSES IN THE INSULATION BARRIER OF COMPRESSED-GAS TANKS

19 DEC 1962

25 pages

Authors: S. M. RIPS; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSONAFB OH

ON THE BASIS OF AN INVESTIGATION OF THE TEMPERATURE FIELD IN VARIOUS TYPES OF INSULATION, HEAT FLOWS (cold losses) are determined both during the cooling of the tank insulation (non steady state) as well as after the temperature field has been established. Illustrative examples ARE GIVEN OF THE CALCULATION FOR LIQUID OXYGEN, NITROGEN, AND HYDROGEN. The proposed method of calculation can be successfully applied to insulation barriers for any other ...

Preliminary Report on Stratastir.

19 SEP 1962

Authors: Charles F. Gerber; NAVY UNDERWATER SOUND LAB NEW LONDON CT

STRATASTIR is a device designed to effect a radical reduction in the thermal gradient of a land-locked body of water deep enough to be stratified by natural environment. The name of this device is derived from it theoretical operation: the mixing or stirring of water strata. (Author)

The Use of High Rotational Speed Techniques as a Laboratory Method for the Study of Mechanical Properties of Metals at Elevated Temperatures.

MAY 1962

Authors: A. R. Kuhlthau; VIRGINIA UNIV CHARLOTTESVILLE RESEARCH LABS FOR THE ENGINEERING SCIENCES

Temperature Gradients in the Wing of a High-Speed Airplane During Dives from High Altitudes

JUL 1948

51 pages

Authors: Thorval Tendeland; Bernard A. Schlaff; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCHCENTER

Flight tests were undertaken to investigate the temperature gradients in the wing structure of a typical high-speed fighter airplane caused by rapid changes in surface temperatures. The tests consisted of measuring the temperatures of the structure throughout the wing (during dives of the airplane from 35000 to 5000 ft, at rates of vertical descent up to 225 ft/sec. The data are presented in the form ...

Quenching - Gun Steel. Quenching Rates and Temperature Differentials in Hollow Cylinders and Gun Tubes.

28 JUL 1944

Authors: J. N. Pappas; V. E. Bender; WATERTOWN ARSENAL LABS MA

Experimental and Computational Study of Area and Perimeter Contributions to Radiometer Forces (Preprint)

7 pages

Authors: N P Selden; E P Muntz; S F Gimelshein; A Alexeenko; A D Ketsdever; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE

The relative contribution to the radiometric force of the area and perimeter of the vane is studied experimentally and numerically. Experimentally, a circle, a low-aspect rectangle, and a high-aspect rectangle were all tested on a thrust measurement stand with nano-Newton resolution placed in a stagnant gas. The computational results were obtained through 2-D simulations using the direct simulation Monte Carlo method, as well as a discrete ordinate solution of the ...