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Side-by-Side Comparisons of Evacuated Compound Parabolic Concentrator and Flat Plate Solar Collector Systems

Description: Three liquid-based solar heating systems employing different types of solar collectors were tested side by side near Chicago, Illinois for one year. The three different types of collectors were: (1) a flat plate collector with a black-chrome coated absorber plate and one low-iron glass cover; (2) an evacuated-tube compound parabolic concentrator (CPC) with a concentration ratio of 1.1, oriented with tubes and troughs along a north-south axis; and (3) an evacuated-tube CPC collector with a conce… more
Date: October 1983
Creator: McGarity, Arthur E.; Allen, John W. & Schertz, William W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Solar District-Heating System Using Seasonal Storage for the Charlestown, Boston Navy Yard Redevelopment Project

Description: A preliminary analysis is presented for a seasonal storage solar heating system for the Charlestown Navy Yard in Boston, Massachusetts. The area occupies a prominent location in the Boston Harbor and is being redeveloped for residential and commercial use. The system makes use of two large, buried concrete storage tanks totaling 5700 cubic meters as a water heat store. Other storage facilities, including a dry dock, offer additional solar opportunities for the navy Yard as the redevelopment pro… more
Date: September 1982
Creator: Breger, Dwayne
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Comparison of the structural efficiency of panels having straight-web and curved-web Y-section stiffeners

Description: Report presenting comparisons of the structural efficiency of panels with straight-web and curved-web Y-section stiffeners. In the high-stress region in which failure is at least in part associated with local buckling, panels with curved-web Y-section stiffeners have higher structural efficiencies than panels with straight-web Y-section stiffeners, which is evidenced by higher average stresses at failure, smaller stiffener heights, or wider average spacing of rivet lines.
Date: January 1949
Creator: Dow, Norris F. & Hickman, William A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charts for Determining Propeller Efficiency

Description: Report presenting a description of a short method of estimating propeller efficiency for a given operating condition. The efficiency is determined for any design condition by evaluating separately from charts the induced losses and the profile-drag losses. The report covers single-rotating propellers of two, three, four, six, and eight blades and includes charts showing the rotational-energy loss for the given operating condition.
Date: September 1944
Creator: Crigler, John L. & Talkin, Herbert W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A theoretical study of the lifting efficiency at supersonic speeds of wings utilizing indirect lift induced by vertical surfaces

Description: Report presenting a theoretical study of the possibility of improving the lifting efficiency of aircraft flying at supersonic speeds using indirect lift, which can be induced on the wing by the fuselage shape and/or wing end plates. Results indicated that lifting efficiency of a planar wing may be improved by favorable interference induced by lateral forces on the end plates or on the sides of the fuselage.
Date: March 26, 1956
Creator: Rossow, Vernon J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Changing the Ratio of Exhaust-Valve Flow Capacity to Inlet-Valve Flow Capacity on Volumetric Efficiency and Output of a Single-Cylinder Engine

Description: Report presenting a series of tests with a single-cylinder engine in order to determine the effect on volumetric efficiency and on engine performance of changing the ratio of exhaust-valve flow capacity to inlet-valve flow capacity when operating with exhaust pressure equal to inlet pressure.
Date: October 1947
Creator: Eppes, James V. D.; Livengood, James C. & Taylor, C. Fayette
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Torque-speed characteristics for high-specific-work turbines

Description: Report presenting an investigation of turbine torque-speed characteristics in a general form using the ideal specific work output corresponding to the turbine static- to total-pressure ratio as the normalizing parameter. The characteristics are first obtained using reference single-, two-, and three-stage analytical efficiency curves in the high-specific-work turbine operating range.
Date: September 1958
Creator: Stewart, Warner L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Propeller Tests on Airplanes

Description: In order to determine the efficiency of a propeller as accurately as possible, its revolution speed, thrust and power absorbed must be measured during flight. Unfortunately, these measurements can only be made with very complicated equipment. To surmount this problem the testers contented themselves with approximate results obtainable in two or three hours of flight.
Date: July 1922
Creator: Senouque, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Investigation of Aircraft Heaters 26: Development of a Sensitive Plated-Type Thermopile for Measuring Radiation

Description: Report presenting an analysis of the factors determining the power efficiency of radiation thermopiles of the type in which receivers consist of parts of conducts themselves or of coatings or other electrically insulating materials in intimate contact with the conductors. Criterions for maximum power efficiency are calculated for these thermopiles, which can then be applied to general thermopile designs.
Date: July 1948
Creator: Boelter, L. M. K.; Dempster, E. R.; Bromberg, R. & Gier, J. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The effect of the wings of single engine airplanes on propulsive efficiency as shown by full scale wind tunnel tests

Description: An investigation was conducted to determine the effect of the wings on propulsive efficiency. The wings are shown to cause a reduction of 1 percent to 3 percent in propulsive efficiency, which is about the same for monoplane as well as biplane wings.
Date: October 1929
Creator: Weick, Fred E. & Wood, Donald H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Power-Off Tests of the Northrop N9M-2 Tailless Airplane in the 40- by 80-Foot Wind Tunnel

Description: Report discussing tests on the N9M-2 airplane to evaluate the airplane efficiency factor and to investigate the characteristics of the aeroboost in the elevon control system. The efficiency factor compared reasonably well to conventional airplanes and the aeroboost system and valve-chatter tests were satisfactory.
Date: December 14, 1944
Creator: Stevens, Victor I., Jr. & McCormack, Gerald M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Simple Means for Saving Fuel on Traffic Flights

Description: Report presenting a discussion of ways to save fuel on traffic flights, including some calculations that can be used for determining fuel efficiency. The primary ways of lessening fuel consumption include flying with a throttled engine and diminished speed.
Date: June 1921
Creator: Kook, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade

Description: In order to determine the maximum and the most favorable pitch for a propeller, it was found desirable to investigate the dependence of propeller efficiency on the angle of attack of the propeller blade. The results of a few experiments are given to show that propeller blades conduct themselves just like airplane wings with reference to the dependence of their efficiency on their angle of attack.
Date: December 1921
Creator: Borck, Hermann
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Efficiency of a Wind Tunnel

Description: If, by some means, a steady state of motion of a perfect fluid were established in an ideal wind tunnel, there would be no losses, and the motion would persist indefinitely. In the actual tunnel, the function of the motor-fan group is overcome by the total loss of head in the tube due to friction and eddies.
Date: February 1922
Creator: Miller, William H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High Efficiency of Seaplanes

Description: A table is presented which includes data for calculating the index of efficiency. The author uses this data to conclude that seaplanes cannot be considered inferior to terrestrial airplanes.
Date: August 1921
Creator: Pegna, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Flight Investigation of a 20-Inch-Diameter Steady-Flow Ram Jet

Description: Memorandum presenting a flight investigation conducted on a 20-inch-diameter steady-flow ramjet at a range of altitudes and free-stream Mach numbers. Results regarding the variation of combustion efficiency with fuel-air ratio and pressure altitude, effects of combustion-chamber-inlet velocity, and altitude on the operating range of fuel-air ratio are provided. The ramjet unit operated smoothly over the entire range of velocities and altitudes with the exception of occasional rough operation at… more
Date: January 14, 1948
Creator: Disher, John H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Preliminary correlation of efficiency of aircraft gas-turbine combustors for different operating conditions

Description: Report presenting a correlation of combustion-efficiency data obtained in experimental investigations with 14 aircraft gas-turbine combustors. The precision is not good for some combustors, but can help in predicting the efficiency at different operating conditions and in comparing the performance of different combustors from data obtained in unrelated tests.
Date: September 21, 1950
Creator: Childs, J. Howard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Combustion-efficiency and altitude-limit investigations of five fuels in an annular turbojet combustor

Description: Report presenting five fuels of boiling temperatures and several hydrocarbon types in a jet-propulsion annular combustor to determine the effect of fuel boiling temperature and paraffinic and aromatic hydrocarbon types on combustion efficiency and altitude operational limit. At the severe inlet-air condition, the highest combustion efficiencies were obtained with the paraffinic and aromatic fuels with low boiling temperatures were found to vary from 30 to 58 percent.
Date: June 7, 1954
Creator: Wear, Jerrold D. & Jonash, Edmund R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of Inlet-Air Parameters on Combustion Limit and Flame Length in 8-Inch-Diameter Ram-Jet Combustion Chamber

Description: Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.
Date: July 22, 1948
Creator: Cervenka, A. J. & Miller, R. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Blade-Section Thickness Ratios on the Aerodynamic Characteristics of Related Full-Scale Propellers at Mach Numbers Up to 0.65

Description: Report discussing an investigation of two full-scale NACA propellers at a range of blade angles and at speeds of up to 500 miles per hour. The results are compared to previous investigations of five NACA propellers to evaluate the effects of blade-section thickness ratios on propeller characteristics.
Date: June 6, 1949
Creator: Maynard, Julian D. & Steinberg, Seymour
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of design changes and operating conditions on combustion and operational performance of a 28-inch diameter ram-jet engine

Description: The results of an altitude test-chamber investigation of the effects of a number of design changes and operating conditions on altitude peformance of a 28-inch diameter ram jet engine are presented. Most of the investigation was for a simulated flight Mach number of 2.0 above the tropopause. Fuel-air distribution, gutter width, the presence of a pilot flame, cimbustion-chamber-inlet temperature, and exhaust-nozzle throat area were found to have significant effects on limits of combustion. Combu… more
Date: February 13, 1952
Creator: Shillito, T. B. & Nakanishi, Shigeo
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Altitude performance of annular combustor type turbojet engine with JFC-2 fuel

Description: An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or lo… more
Date: February 5, 1952
Creator: Useller, James W.; Harp, James L., Jr. & Barson, Zelmar
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Turbojet combustion efficiency at high altitudes

Description: Report presenting research on the single problem of combustion efficiency of turbojet engines at high altitudes. Representative results of investigations with turbojet combustors are presented to analyze trends regarding combustor operating variables, combustor-design variables, and fuel variables.
Date: October 27, 1950
Creator: Olson, Walter T.; Childs, J. Howard & Jonash, Edmund R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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