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Exploratory investigation of external stores in the aerodynamic characteristics of a 1/16-scale model of the Douglas D-558-II research airplane at a Mach number of 2.01

Description: Report presenting an investigation of stores on the Douglas D-558-II research airplane in the wind tunnel and in flight using various store configurations. The drag measured for all store configurations was high, from two to three times the free-air drag estimated for the store and pylon. Results regarding longitudinal characteristics and lateral characteristics are provided.
Date: August 25, 1954
Creator: Smith, Norman F.
Partner: UNT Libraries Government Documents Department

The origin and distribution of supersonic interference from measurement of individual forces on several wing-fuselage-store configurations 6: swept-wing heavy-bomber configuration with stores of different sizes and shapes

Description: Report presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.61. The separate forces on a store, a fuselage, a swept wing, and a swept-wing-fuselage combination were measured. Results regarding drag, lift, pitching moment, side force, and yawing moment are provided.
Date: March 8, 1956
Creator: Smith, Norman F.
Partner: UNT Libraries Government Documents Department

NACA Mach number indicator for use in high-speed tunnels

Description: Report presenting a description of a device for indicating stream Mach number in a high-speed tunnel. It consists of a mechanism for determining the pressure ratio that Mach number is a function of. The instrument is in service in the 8-foot high-speed tunnel and its accuracy has been found adequate for wind-tunnel requirements.
Date: July 1943
Creator: Smith, Norman F.
Partner: UNT Libraries Government Documents Department

Numerical evaluation of mass-flow coefficient and associated parameters from wake-survey equations

Description: Report presenting a method for the determination by use of charts of mass-flow coefficient and associated flow parameters from pressure surveys in internal-flow systems. The charts presented cover a wide range of specific parameters through the complete range of subsonic Mach numbers. The equations have also been evaluated for flows that involve the adding of mechanical or thermal energy, such as flows behind radiators or propellers.
Date: August 1947
Creator: Smith, Norman F.
Partner: UNT Libraries Government Documents Department

High-speed investigation of low-drag wing inlets

Description: Report presenting tests of a low-drag wing-inlet section at high speeds in the 8-foot high-speed tunnel. Satisfactory section characteristics could be obtained only for a small range of angle of attack and inlet-velocity ratio, as a result of internal separation and external pressure peaks. Results regarding external-flow conditions, internal-flow conditions, section characteristics, modifications, and design considerations are provided.
Date: September 1944
Creator: Smith, Norman F.
Partner: UNT Libraries Government Documents Department

An investigation of a supersonic aircraft configuration having a tapered wing with circular-arc sections and 40 degree sweepback: force characteristics of the complete configuration and its various components at Mach numbers of 1.40 and 1.59

Description: Report presenting an investigation of a supersonic aircraft configuration and various combinations of its components at a range of Mach numbers. Longitudinal- and lateral-force characteristics of the configurations, as well as longitudinal- and lateral-stability derivatives, are provided.
Date: January 22, 1951
Creator: Smith, Norman F. & Marte, Jack E.
Partner: UNT Libraries Government Documents Department

Measurement of static forces on internally carried bombs of three fineness ratios in flow field of a swept-wing fighter-bomber configuration at a Mach number of 1.61 with illustrative drop-path calculations

Description: Report presenting a wind-tunnel investigation of bomb-release problems by measuring static forces for computation of bomb drop paths. Forces and moments were measured on bombs of three fineness ratios and on a swept-wing fighter-bomber airplane for various positions of the bomb under an open bomb bay. The wing of the plane is shown to have a significant effect on the bomb forces before and after the bomb emerged from the bomb bay.
Date: January 10, 1957
Creator: Smith, Norman F. & Carlson, Harry W.
Partner: UNT Libraries Government Documents Department

Measurement of static forces on internally carried bombs of three fineness ratios in flow field of a swept-wing fighter-bomber configuration at a Mach number of 1.61 with illustrative drop path calculations

Description: Report presenting a wind-tunnel investigation of bomb-release problems by measuring static forces for computation of bomb drop paths. Forces and moments were measured on bombs of three fineness ratios and on a swept-wing fighter-bomber configuration for several positions of the bomb under an open bomb bay. Results regarding contour paths and drop-path calculations are provided.
Date: January 10, 1957
Creator: Smith, Norman F. & Carlson, Harry W.
Partner: UNT Libraries Government Documents Department

Some effects of configuration variables on store loads at supersonic speeds

Description: Report presenting an analysis and examination of a large volume of data from several recent stores-research programs. For a given wing plan form, store position and configuration of angle of attack have been shown to be the most important parameters in the evaluation of store side force.
Date: July 6, 1955
Creator: Smith, Norman F. & Carlson, Harry W.
Partner: UNT Libraries Government Documents Department

An investigation of the characteristics of three NACA 1-series nose inlets at subcritical and supercritical Mach numbers

Description: Report presenting an investigation of the characteristics of three representative NACA 1-series nose inlets over a Mach number range extending from 0.4 to 0.925 in the high-speed wind tunnel. Results regarding pressure distribution, drag, and some potential design considerations are provided.
Date: January 13, 1949
Creator: Pendley, Robert E. & Smith, Norman F.
Partner: UNT Libraries Government Documents Department

The origin and distribution of supersonic store interference from measurement of individual forces on several wing-fuselage-store configurations 3: swept-wing fighter-bomber configuration with large and small stores. Mach number 1.61

Description: Report presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.61. Separate forces on a store, a swept wing, and a swept-wing-fuselage combination were measured. This report presents data on a configuration that simulated a fighter-bomber airplane with a large and a small external store.
Date: September 15, 1955
Creator: Smith, Norman F. & Carlson, Harry W.
Partner: UNT Libraries Government Documents Department

As Investigation at Mach Numbers of 1.41 and 2.01 of the Aerodynamic Characteristics of an 0.025-scale Model of the MX-1712

Description: "An investigation of the aerodynamic characteristics of an 0.025-scale model of the MX-1712 configuration has been conducted in the Langley 4- by 4-foot supersonic pressure tunnel. The tests were performed at Mach numbers of 1.41 and 2.01 at a Reynolds number of approximately 2.6 x 10(exp 6) based on the wing mean aerodynamic chord. The MX-1712 is a proposed swept-wing, jet-powered supersonic bomber aircraft. The wing is of aspect ratio 3.5, taper ratio 0.2, and thickness ratio 5.5 percent (streamwise) and has 47deg sweep of the quarter-chord line" (p. 1).
Date: October 17, 1952
Creator: Smith, Norman F. & Hasel, Lowell E.
Partner: UNT Libraries Government Documents Department

An investigation at Mach numbers of 1.41 and 2.01 of the aerodynamic characteristics of a swept-wing supersonic bomber configuration

Description: Report presenting an investigation of a swept-wing supersonic bomber configuration in the 4- by 4-foot supersonic pressure tunnel. Testing occurred at Mach numbers of 1.41 and 2.01 and a designated Reynolds number based on the wing mean aerodynamic chord. The model had a tapered wing with an aspect ratio of 3.5, a taper ratio of 0.2, a thickness ratio of 5.5 percent and 47 degrees sweep of the quarter-chord line. The investigation included the longitudinal and lateral force characteristics and various combinations of its components, including several jet nacelle installations.
Date: February 1, 1956
Creator: Smith, Norman F. & Hasel, Lowell E.
Partner: UNT Libraries Government Documents Department

Aerodynamic tests of an M-31 bomb in the 8-foot high-speed tunnel

Description: Report presenting aerodynamic tests of a 300-pound M-31 demolition bomb. Force tests at a range of angles of attack were made at Mach number 0.725, which corresponds to a speed of 810 feet per second at sea level. Results regard the drag, lift, and pitching moment are provided.
Date: August 1942
Creator: Baals, Donald D.
Partner: UNT Libraries Government Documents Department

An investigation of a supersonic aircraft configuration having a tapered wing with circular-arc section and 40 degree sweepback: a pressure-distribution study of the aerodynamic characteristics of the wing at Mach number 1.40

Description: Report discussing a pressure-distribution investigation of a wing of a supersonic aircraft in the presence of a fuselage at a specified Mach number and aerodynamic chord. The wing had a quarter chord swept back 40 degrees, an aspect ratio of 4, a taper ratio of 0.5, and 10-percent-thick circular-arc sections perpendicular to the quarter-chord line. The results were compared to a similar investigation at a different Mach number.
Date: April 20, 1951
Creator: Smith, Norman F.; Kainer, Julian H. & Webster, Robert A.
Partner: UNT Libraries Government Documents Department

Development of Characterization Tools for Reliability Testing of MicroElectroMechanical System Actuators

Description: Characterization tools have been developed to study the performance characteristics and reliability of surface micromachined actuators. These tools include (1) the ability to electrically stimulate or stress the actuator, (2) the capability to visually inspect the devices in operation, (3) a method for capturing operational information, and (4) a method to extract performance characteristics from the operational information. Additionally, a novel test structure has been developed to measure electrostatic forces developed by a comb drive actuator.
Date: July 26, 1999
Creator: Allen, James J.; Eaton, William P.; Smith, Norman F. & Tanner, Danelle M.
Partner: UNT Libraries Government Documents Department

The development and application of high-critical-speed nose inlets

Description: From Summary: "An analysis of the nose-inlet shapes developed in previous investigations to represent the optimum from the standpoint of critical speed has shown that marked similarity exists between the nondimensional profiles of inlets which have widely different proportions and critical speeds. With the nondimensional similarity of such profiles established, the large differences in the critical speeds of these nose inlets must be a function of their proportions. An investigation was undertaken in the Langley 8-foot high-speed tunnel to establish the effects of nose-inlet proportions on critical Mach number and to develop a rational method for the design of high-critical-speed nose inlets to meet desired requirements."
Date: July 1945
Creator: Baals, Donald D.; Smith, Norman F. & Wright, John B.
Partner: UNT Libraries Government Documents Department

The development and application of high-critical-speed nose inlets

Description: From Summary: "An analysis of the nose-inlet shapes developed in previous investigations to represent the optimum from the standpoint of critical speed has shown that marked similarity exists between the nondimensional profiles of inlets which have widely different proportions and critical speeds. With the nondimensional similarity of such profiles established, the large differences in the critical speeds of these nose inlets must be a function of their proportions. An investigation was undertaken in the Langley 8-foot high-speed tunnel to establish the effects of nose-inlet proportions on critical Mach number to develop a rational method for the design of high-critical-speed nose inlets to meet desired requirements."
Date: June 8, 1945
Creator: Baals, Donald D.; Smith, Norman F. & Wright, John B.
Partner: UNT Libraries Government Documents Department

Microdiagnostic Lab on a Chip - LDRD Final Report

Description: Polycrystalline silicon (polysilicon) surface micromachining is a new technology for building micrometer ({micro}m) scale mechanical devices on silicon wafers using techniques and process tools borrowed from the manufacture of integrated circuits. Sandia National Laboratories has invested a significant effort in demonstrating the viability of polysilicon surface micromachining and has developed the Sandia Ultraplanar Micromachining Technology (SUMMiT V{trademark} ) process, which consists of five structural levels of polysilicon. A major advantage of polysilicon surface micromachining over other micromachining methods is that thousands to millions of thin film mechanical devices can be built on multiple wafers in a single fabrication lot and will operate without post-processing assembly. However, if thin film mechanical or surface properties do not lie within certain tightly set bounds, micromachined devices will fail and yield will be low. This results in high fabrication costs to attain a certain number of working devices. An important factor in determining the yield of devices in this parallel-processing method is the uniformity of these properties across a wafer and from wafer to wafer. No metrology tool exists that can routinely and accurately quantify such properties. Such a tool would enable micromachining process engineers to understand trends and thereby improve yield of micromachined devices. In this LDRD project, we demonstrated the feasibility of and made significant progress towards automatically mapping mechanical and surface properties of thin films across a wafer. The MEMS parametrics measurement team has implemented a subset of this platform, and approximately 30 wafer lots have been characterized. While more remains to be done to achieve routine characterization of all these properties, we have demonstrated the essential technologies. These include: (1) well-understood test structures fabricated side-by-side with MEMS devices, (2) well-developed analysis methods, (3) new metrologies (i.e., long working distance interferometry) and (4) a hardware/software platform that integrates (1), (2) and ...
Date: March 1, 2002
Creator: DE BOER, MAARTEN P.; SMITH, NORMAN F.; SINCLAIR, MICHAEL B.; BAKER, MICHAEL S. & BITSIE, FERNANDO
Partner: UNT Libraries Government Documents Department

MEMS reliability in a vibration environment

Description: MicroElectricalMechanical Systems (MEMS) were subjected to a vibration environment that had a peak acceleration of 120g and spanned frequencies from 20 to 2000 Hz. The device chosen for this test was a surface-micromachined microengine because it possesses many elements (springs, gears, rubbing surfaces) that may be susceptible to vibration. The microengines were unpowered during the test. The authors observed 2 vibration-related failures and 3 electrical failures out of 22 microengines tested. Surprisingly, the electrical failures also arose in four microengines in the control group indicating that they were not vibration related. Failure analysis revealed that the electrical failures were due to shorting of stationary comb fingers to the ground plane.
Date: February 3, 2000
Creator: TANNER,DANELLE M.; WALRAVEN,JEREMY A.; HELGESEN,KAREN SUE; IRWIN,LLOYD W.; GREGORY,DANNY LYNN; STAKE,JOHN R. et al.
Partner: UNT Libraries Government Documents Department

MEMS reliability in shock environments

Description: In order to determine the susceptibility of the MEMS (MicroElectroMechanical Systems) devices to shock, tests were performed using haversine shock pulses with widths of 1 to 0.2 ms in the range from 500g to 40,000g. The authors chose a surface-micromachined microengine because it has all the components needed for evaluation: springs that flex, gears that are anchored, and clamps and spring stops to maintain alignment. The microengines, which were unpowered for the tests, performed quite well at most shock levels with a majority functioning after the impact. Debris from the die edges moved at levels greater than 4,000g causing shorts in the actuators and posing reliability concerns. The coupling agent used to prevent stiction in the MEMS release weakened the die-attach bond, which produced failures at 10,000g and above. At 20,000g the authors began to observe structural damage in some of the thin flexures and 2.5-micron diameter pin joints. The authors observed electrical failures caused by the movement of debris. Additionally, they observed a new failure mode where stationary comb fingers contact the ground plane resulting in electrical shorts. These new failure were observed in the control group indicating that they were not shock related.
Date: February 9, 2000
Creator: TANNER,DANELLE M.; WALRAVEN,JEREMY A.; HELGESEN,KAREN SUE; IRWIN,LLOYD W.; BROWN,FREDERICK A.; SMITH,NORMAN F. et al.
Partner: UNT Libraries Government Documents Department

MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

Description: The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.
Date: January 1, 2000
Creator: TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH et al.
Partner: UNT Libraries Government Documents Department