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The Measurement of Pressure Through Tubes in Pressure Distribution Tests

Description: "The tests described in this report were made to determine the error caused by using small tubes to connect orifices on the surface of aircraft to central pressure capsules in making pressure distribution tests. Aluminum tubes of 3/16-inch inside diameter were used to determine this error. Lengths from 20 feet to 226 feet and pressures whose maxima varied from 2 inches to 140 inches of water were used. Single-pressure impulses for which the time of rise of pressure from zero to a maximum varied from 0.25 second to 3 seconds were investigated" (p. 303).
Date: February 23, 1927
Creator: Hemke, Paul E.
Partner: UNT Libraries Government Documents Department

A Miniature Electrical Pressure Gage Utilizing a Stretched Flat Diagram

Description: "A variable-air-gap, inductance-type, electrical pressure gage is described that is basically 7/16 inch in diameter and 1/4 inch in thickness. The gage was designed to measure accurately pressures fluctuating at high frequencies and has proved to be a value as a general-purpose electrical gage for aeronautical work where small size and minimum response to acceleration forces are important factors. Design equations and curves are presented which can be used to predict the deflections and fundamental natural frequencies of stretched flat diaphragms" (p. 1).
Date: April 1952
Creator: Patterson, John L.
Partner: UNT Libraries Government Documents Department

High-altitude performance of an experimental turbojet combustor having variable primary-air admission

Description: Report presenting an investigation of 47 experimental tubular designs embodying variable primary-air openings to control the fuel-air ratio in the combustion zone at simulated high-altitude operating conditions for a representative 5.2-pressure-ratio engine. The performance characteristics considered were combustion efficiency, operating range, and pressure loss. Results regarding the effect of fuel injector design, effect of primary-air baffles, and performance characteristics of the best models are provided.
Date: April 11, 1955
Creator: Straight, David M. & Gernon, J. Dean
Partner: UNT Libraries Government Documents Department

Pressure of air on coming to rest from various speeds

Description: The text gives theoretical formulas from which is computed a table for the pressure of air on coming to rest from various speeds, such as those of aircraft and propeller blades. Pressure graphs are given for speeds from 1 cm. Sec. up to those of swift projectiles.
Date: 1927
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of a Number of Total Pressure Tubes at High Angles of Attack

Description: Report presenting a wind-tunnel investigation to determine the effect of inclination of the air stream on the measured pressures of 20 total-pressure tubes through a range of angles of attack and Mach numbers. Generally, the range of angle of attack over which the tubes remained insensitive to inclination was appreciably greater at supersonic speeds than at subsonic speeds.
Date: January 1951
Creator: Gracey, William; Coletti, Donald E. & Russell, Walter R.
Partner: UNT Libraries Government Documents Department

Orientation of orifices on bodies of revolution for determination of stream static pressure at supersonic speeds

Description: Report presenting experimental data obtained in the 4- by 4-foot supersonic tunnel for a parabolic body of revolution of large fineness ratio at mach number 1.59, which are analyzed in order to locate positions at which static-pressure orifices will indicate a constant static pressure independent of the pitch-yaw attitude of the body.
Date: January 1952
Creator: Cooper, Morton & Hamilton, Clyde V.
Partner: UNT Libraries Government Documents Department

Analytical and experimental investigation of 90 degrees supersonic turning passages suitable for supersonic compressors or turbines

Description: From Summary: "Four 90 degree two-dimensional turning passages designed by the method of characteristics were tested at an inlet Mach number of 1.71. The measured losses varied from 5 to 15 percent of the inlet stagnation pressure. The smallest loss was obtained for a passage in which separation on the convex surface was minimized through the introduction of a favorable pressure gradient."
Date: September 12, 1949
Creator: Liccini, Luke L.
Partner: UNT Libraries Government Documents Department

A flight investigation of fuselage static-pressure-vent airspeed installations

Description: Report presenting an investigation to determine the departure of the static pressure measured at fuselage static-pressure vents from the static pressure of the ambient air. Several locations for fuselage static-pressure vents on an XB-24F and a Lockheed 12A airplane.
Date: November 1943
Creator: Scherrer, Richard & Rodert, Lewis A.
Partner: UNT Libraries Government Documents Department

Behavior of Static Pressure Heads at High Speeds

Description: "Memorandum presenting the development of a static pressure head for high speeds. These tests proved the practicability of static pressure heads at speeds up to 400 km/h (248.5 mph). It weighs 6.5 kg or 2.5 times as much as the old head. The position of the pressure head below the airplane was determined by bearing method at different speeds and for different lengths of suspension" (p. 1).
Date: June 1938
Creator: Danielzig, Helmut
Partner: UNT Libraries Government Documents Department

Measurement of Static Pressure on Aircraft

Description: "Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to flow. Errors which result from variations in the configuration of static-pressure vents are also presented" (p. 645).
Date: December 17, 1956
Creator: Gracey, William
Partner: UNT Libraries Government Documents Department

Measurement of Static Pressure on Aircraft

Description: Note presenting existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to the flow.
Date: November 1957
Creator: Gracey, William
Partner: UNT Libraries Government Documents Department

The Changeable Interaction between Soils and Pressure Cells: Tests and Reviews at the Waterways Experiment Station

Description: Partial abstract: "The principal subjects of the report are the often neglected changes in the interaction of soil and pressure cells with consequent changes in relative errors in cell registrations. The report contains (a) a brief account of the development and use of soil pressure cells; (b) a review of proposed theories for soil-cell interaction; (c) a delayed account of tests with Waterways Experiment Station pressure cells placed in a large triaxial device; and (d) tentative conclusions plus suggestions for calibration, installation, and measuring procedures."
Date: June 1976
Creator: Hvorslev, Mikael Juul
Partner: UNT Libraries Government Documents Department

Measurement of static pressure on aircraft

Description: From Summary: "Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is included to the flow. Errors due to variations in the configuration of static-pressure vents are also presented."
Date: April 1, 1957
Creator: Gracey, William
Partner: UNT Libraries Government Documents Department

Cuff-less Blood Pressure Measurement Using a Smart Phone

Description: Blood pressure is vital sign information that physicians often need as preliminary data for immediate intervention during emergency situations or for regular monitoring of people with cardiovascular diseases. Despite the availability of portable blood pressure meters in the market, they are not regularly carried by people, creating a need for an ultra-portable measurement platform or device that can be easily carried and used at all times. One such device is the smartphone which, according to comScore survey is used by 26.2% of the US adult population. the mass production of these phones with built-in sensors and high computation power has created numerous possibilities for application development in different domains including biomedical. Motivated by this capability and their extensive usage, this thesis focuses on developing a blood pressure measurement platform on smartphones. Specifically, I developed a blood pressure measurement system on a smart phone using the built-in camera and a customized external microphone. the system consists of first obtaining heart beats using the microphone and finger pulse with the camera, and finally calculating the blood pressure using the recorded data. I developed techniques for finding the best location for obtaining the data, making the system usable by all categories of people. the proposed system resulted in accuracies between 90-100%, when compared to traditional blood pressure meters. the second part of this thesis presents a new system for remote heart beat monitoring using the smart phone. with the proposed system, heart beats can be transferred live by patients and monitored by physicians remotely for diagnosis. the proposed blood pressure measurement and remote monitoring systems will be able to facilitate information acquisition and decision making by the 9-1-1 operators.
Date: May 2012
Creator: Jonnada, Srikanth
Partner: UNT Libraries

The Vapor Pressure of Arsenic Trioxide

Description: Technical paper issued by the Bureau of Mines over investigations of vapor pressure. The methods and equipment used for the investigations are presented. The results are discussed. This paper includes tables, illustrations, and photographs.
Date: March 1915
Creator: Welch, H. V. & Duschak, L. H.
Partner: UNT Libraries Government Documents Department

Comparison of experimental with theoretical total-pressure loss in parallel-walled turbojet combustors

Description: "An experimental investigation of combustor total-pressure loss was undertaken to confirm previous theoretical analyses of effects of geometric and flow variables and of heat addition. The results indicate that a reasonable estimate of cold-flow total-pressure-loss coefficient may be obtained from the theoretical analyses. Calculated total-pressure loss due to heat addition agreed with experimental data only when there was no flame ejection from the liner at the upstream air-entry holes" (p. 1).
Date: January 9, 1957
Creator: Dittrich, Ralph T.
Partner: UNT Libraries Government Documents Department

A high-speed engine pressure indicator of the balanced diaphragm type

Description: This report describes a pressure-measuring device especially adapted for use in mapping indicator diagrams of high-speed internal combustion engines. The cards are obtained by a point-to-point method giving the average of a large number of engine cycles. The principle involved is the balancing of the engine cylinder pressure against a measured pressure on the opposite side of the metal a diaphragm of negligible stiffness.
Date: 1921
Creator: Dickinson, H. C. & Newell, F. B.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation at Mach 1.9 of multijet-missile base pressures

Description: From Summary: "An experimental wind-tunnel investigation was conducted at Mach 1.9 to determine the pressures acting on the base of a multijet missile using unheated air and carbon dioxide as jet fluids. The variation of base pressure with jet static-pressure ratio was compared with results estimated for an axisymmetric single-jet model and some correlation was observed."
Date: March 3, 1955
Creator: Baughman, L. Eugene
Partner: UNT Libraries Government Documents Department

Pressure lag in tubing used in flight research

Description: From Introduction: "Tests described in this report were undertaken to obtain a quantitative measure of the pressure lag in typical pressure-tubing systems used by the Ames Aeronautical Laboratory in flight research investigations. Lag measurements were made with both single-direction and oscillating pressure changes. Single-direction pressure changes were investigated to determine if the lag in orifice-pressure lines and in the research airspeed and altitude measuring systems of pursuit-type airplane undergoing flight tests was sufficient to cause an appreciable error in the record of a sudden pressure change. Oscillating pressure changes were investigated with particular reference to the accuracy of pressure peaks in pressure-distribution measurements during the time of buffeting conditions as found in stalls."
Date: July 1945
Creator: Turner, Howard L. & Rathert, George A., Jr.
Partner: UNT Libraries Government Documents Department

Pressure measurements on a sharply converging fuselage afterbody with jet on and off at Mach numbers from 0.8 to 1.6

Description: Report presenting testing of a rocket-powered model of a fin-stabilized parabolic body of revolution with fineness ratio 8.91 and maximum diameter at 80 percent of body station at a range of Mach numbers to determine the static pressures at two orifices on the rearward side of the stabilizing fins. Results regarding measured pressures, comparison of theory and experiment, and drag are provided.
Date: August 10, 1950
Creator: Stoney, William E., Jr. & Katz, Ellis
Partner: UNT Libraries Government Documents Department

Wing-flow study of pressure-drag reduction at transonic speed by projecting a jet of air from the nose of a prolate spheroid of fineness ratio 6

Description: Report presenting a study of the pressure-drag reduction obtained by projecting a high-energy jet of air from the nose of a prolate spheroid at transonic speeds. Results regarding the pressure distribution on the body, pressure drag, shadowgraphs, and some notes regarding the slope of the body and level of shear at the jet exit are provided.
Date: October 26, 1951
Creator: Lopatoff, Mitchell
Partner: UNT Libraries Government Documents Department