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Pressure drop across finned cylinders enclosed in a jacket

Description: The pressure drop across finned cylinders in a jacket for a range of air speeds from approximately 13 to 230 miles per hour has been investigated. Tests were made to determine the effect on the pressure drop of changes in fin space, fin width, jacket entrance and exit areas, skirt-approach radius, and the use of fillets and a separator plate at the rear of the cylinder. The pressure drop across the cylinder increased as the fin space decreased, the increase being very rapid at fin spaces smaller than approximately 0.20 inch. Fin width had little effect on the pressure drop for the range of widths tested. The pressure drop across the cylinder was nearly halved by increasing the skirt-approach radius from 3/4 inch to 1-1/4 inches, but fillets and a separator plate at the rear of the cylinder had little effect on the pressure drop. The pressure drop across a cylinder with tapered fins was greater than that for a cylinder having rectangular fins with the same effective fin spacing.
Date: November 1937
Creator: Rollin, Vern G. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

Method for determining pressure drop of air flowing through constant-area passages for arbitrary heat-input distributions

Description: Report presenting a method for convenient determination of the pressure drop sustained by air flowing at high subsonic speeds in a constant-area passage under the simultaneous influence of friction and heat addition. Air-pressure-drop working charts based on the method are presented.
Date: September 1950
Creator: Pinkel, Benjamin; Noyes, Robert N. & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

Description: "Theoretical investigations have shown that, because air is compressible, the pressure-drop requirements for cooling an air-cooled engine will be much greater at high altitudes and high speeds than at sea level and low speeds. Tests were conducted by the NACA to obtain some experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. The results reported in the present paper are regarded as preliminary to tests on single-cylinder and multi-cylinder engines. Tests were conducted over a wide range of air flows and density altitudes" (p. 185).
Date: July 1, 1944
Creator: Goldstein, Arthur W. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

Description: "Theoretical investigations have shown that, because air is compressible, the pressure-drop requirements for cooling an air-cooled engine will be much greater at high altitudes and high speeds than at sea level and low speeds. Tests were conducted by the NACA to obtain some experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. The results reported in the present paper are regarded as preliminary to tests on single-cylinder and multicylinder engines. Tests were conducted over a wide range of air flows and density altitudes" (p. 1).
Date: July 1, 1944
Creator: Goldstein, Arthur W. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 23: measured and predicted performance of a flat-plate type exhaust gas and air heat exchanger

Description: Report presenting results of tests of the thermal performance and the static pressure drop characteristics of a flat-plate type exhaust gas and air heat exchanger. The ventilating air shroud built into the heat exchanger gives characteristics of cross flow and parallel flow.
Date: April 1945
Creator: Boelter, L. M. K.; Guibert, A. G.; Rademacher, J. M. & Sanders, V. D.
Partner: UNT Libraries Government Documents Department

Pressure-drop characteristics of a 22-segment mock-up of the General Electric Company air-cooled aircraft reactor

Description: Report presenting an investigation to obtain pressure-drop data for flow of air with no heat addition on a 22-segment mock-up of the GE aircraft reactor. Pressure-drop data were obtained over a range of Reynolds numbers, Mach numbers, and inlet-air pressures.
Date: January 20, 1955
Creator: Sams, Eldon W. & Weiland, Walter F., Jr.
Partner: UNT Libraries Government Documents Department

Measurements of Pressure Drop with No Heat Addition on Mockup Segments of the General Electric Air-Cooled Aircraft Reactor

Description: "An investigation was conducted at the NACA Lewis laboratory to obtain pressure-drop data for flow of air with no heat addition through mockups of two reactor segments of the proposed General Electric Company aircraft reactor. Pressure-drop data were obtained over a range of Reynolds numbers from 4000 to 80,000, air inlet Mach numbers from 0.02 to 0.40, inlet pressures up to about 40 inches of mercury absolute, and ambient air temperatures. factors, corrected for entrance, vena contracta, momentum, and exit losses, are considerably higher at the high Reynolds numbers than those reported for turbulent flow in smooth pipes" (p. 1).
Date: November 7, 1952
Creator: Sams, Eldon W. & Nagey, Tibor F.
Partner: UNT Libraries Government Documents Department

Pressure Drop in Tubing in Aircraft Instrument Installations

Description: "The theoretical basis of calculation of pressure drop in tubing is reviewed briefly. The effect of pressure drop in connecting tubing upon the operation and indication of aircraft instruments is discussed. Approximate equations are developed, and charts and tables based upon them are presented for use in designing installations of altimeters, air-speed indicators, rate-of-climb indicators, and air-driven gyroscopic instruments" (p. 1).
Date: February 1937
Creator: Wildhack, W. A.
Partner: UNT Libraries Government Documents Department

Pressure-Drop Characteristics of Orifice Plates Used to Simulate Radiators

Description: Report presenting an investigation of the pressure-drop characteristics of orifice plates, which has been conducted to facilitate the design of resistances to simulate various types of cooling units. This use of the orifice plates was found to be practical because of the simple construction of the plates, the ease of which pressure drop can be varied by use of corks, and the absence of any large scale effects.
Date: March 1942
Creator: Czarnecki, K. R.
Partner: UNT Libraries Government Documents Department

Simple Curves for Determining the Effects of Compressibility on Pressure Drop Through Radiators

Description: Report presenting simple curves by which the basic pressure-drop characteristics of unheated tubular radiators can be corrected to operating conditions in which the radiator is heated and in which the Mach number of the tube flow is of appreciable magnitude. The only data required for the use of the curves are the radiator dimensions, the rate of heat input, the pressure and temperature ahead of the radiator, and the rate of mass flow of air through the radiator.
Date: September 1944
Creator: Becker, John V. & Baals, Donald D.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Entrance-Region Heat-Transfer Coefficients

Description: "Experimental results of tests made at the Langley Memorial Aeronautical Laboratory are presented to show how heat-transfer coefficients can be increased by a method utilizing the high rate of heat transfer known to exist on any heat-transfer surface in the region adjacent to the edge on which the cooling or heating fluid impinges. The results show that, for the same pressure drop, the average surface heat-transfer.coefficient can be increased 50 to 100 percent when a cooling surface having a length of four inches in the direction of fluid flow is cut to form twenty fins with a length of 0.2 inch in the direction of fluid flow and the fins are sharpened and staggered in the air stream" (p. 1).
Date: November 1943
Creator: Joyner, Upshur T.
Partner: UNT Libraries Government Documents Department

Chart for simplifying calculations of pressure drop of a high-speed compressible fluid under simultaneous action of friction and heat transfer - application to combustion-chamber cooling passages

Description: Report presenting a method for calculating the pressure drop of a high-speed compressible fluid in a constant-area duct under the simultaneous action of friction and heat transfer. The temperature distribution assumed in the development of the working chart can be made to closely approximate, in on one or two steps, the temperature distributions found in the cooling passages of ramjet and tail-pipe-burner combustion chambers.
Date: March 1950
Creator: Sibulkin, Merwin & Koffel, William K.
Partner: UNT Libraries Government Documents Department

Flow Tests of an NACA-Designed Supercharger Inlet Elbow and the Effects of Various Components on the Flow Characteristics at the Elbow Outlet

Description: Note presenting an investigation on a supercharger inlet elbow designed to have a uniform velocity distribution at the outlet with a minimum pressure loss through the bend. The effects of a vane, an impeller-shaft housing, and the combination of the two on the outlet-velocity distribution and total pressure drop through the elbow were determined.
Date: October 1946
Creator: Guentert, D. C.; Todd, D. J. & Simmons, W. P., Jr.
Partner: UNT Libraries Government Documents Department

Experimental Determination of Pressure Drop Caused by Wire Gauze in an Air Stream

Description: "For several kinds of wire gauze the difference in static, dynamic and total or absolute pressure in front of and behind the gauze were determined for comparison with the pressure drop caused by an airplane radiator, such gauze being used on airplane models to represent the radiator" (p. 1).
Date: January 1925
Partner: UNT Libraries Government Documents Department

Compressibility Effects on Heat Transfer and Pressure Drop in Smooth Cylindrical Tubes

Description: "An analysis is made to simplify pressure-drop calculations for nonadiabatic and adiabatic friction flow of air in smooth cylindrical tubes when the density changes due to heat transfer and pressure drop are appreciable. Solutions of the equation of motion are obtained by the use of Reynolds' analogy between heat transfer and skin friction. Charts of the solutions are presented for making pressure-drop calculations" (p. 1).
Date: October 1944
Creator: Nielsen, Jack N.
Partner: UNT Libraries Government Documents Department

Scale-Up of Alternate HRT Core

Description: "In order to determine the factors involved in the scale-up of cores with concentric inlet and outlet pipes, a 48 inch carbon steel flow model, geometrically similar to a 6 foot diameter core, has been assembled and tested...Visual studies were made of dye and gas behavior in the sphere, and quantitative measurements of point residence times were obtained through the use of conductivity cells actuating a Brush recorder. Static pressure drop across the core was measured."
Date: May 7, 1954
Creator: Lesem, L. B. & Harley, P. H.
Partner: UNT Libraries Government Documents Department

High-Altitude Cooling 2: Air-Cooled Engines

Description: Report presenting the heat-transfer theory for air-cooled engines and an analysis of the cooling pressure drop for the case in which the pressure drop is an appreciable fraction of the absolute pressure. A chart is given for the simple determination of the cooling pressure drop predicted on the basis of the usual type of sea-level cooling-correlation tests.
Date: September 1944
Creator: Williams, David T.
Partner: UNT Libraries Government Documents Department

Two-Phase Frictional Pressure Drop Multipliers for SUVA R-134a Flowing in a Rectangular Duct

Description: The adiabatic two-phase frictional multipliers for SUVA, R-134a flowing in a rectangular duct (with D{sub H} = 4.8 mm) have been measured for 3 nominal system pressures (0.9 MPa, 1.38 MPa and 2.41 MPa) and 3 nominal mass fluxes (510, 1020 and 2040 kg/m{sup 2}/s). The data is compared with several classical correlations to assess their predictive capabilities. The Lockhart-Martinelli model gives reasonable results at the lowest pressure and mass flux, near the operating range of most refrigeration systems, but gives increasingly poor comparisons as the pressure and mass flux is increased. The Chisholm B-coefficient model is found to best predict the data over the entire range of test conditions; however, there is significant disagreement at the highest pressure tested (with the model over predicting the data upwards of 100% for some cases). The data shows an increased tendency toward homogeneous flow as the pressure and flow rate are increased, and in fact the homogeneous model best predicts the bulk of the data at the highest pressure tested.
Date: December 13, 2004
Creator: Vassallo, P & Keller, K
Partner: UNT Libraries Government Documents Department

Axial Pressure Drop Measurements during Pilot-Scale Testing of a Mott Crossflow Filter

Description: The Department of Energy selected CSSX as the preferred cesium removal technology for Savannah River Site waste. As a pretreatment step for the CSSX flowsheet, personnel contact the incoming salt solution that contains entrained sludge with MST to adsorb strontium and select actinides. They filter the resulting slurry to remove the sludge and MST. The filtrate receives further treatment to remove cesium in the solvent extraction system. The baseline filtration technology uses a Mott crossflow filter. We conducted pilot-scale crossflow filter testing with simulated SRS high level waste to evaluate the impact of operating parameters on the crossflow filtration process. The tests employed 0.5 micron and 0.1 micron filters. The feed slurries for these tests included simulated sludge plus MST, simulated sludge only, and simulated sludge plus manganese oxide solids. The supernate for these tests consisted of 5.6-6.4 M sodium, average salt solution. During the tests, we measured the axial pressure drop as a function of axial velocity, feed slurry, and insoluble solids concentration. This report documents the axial pressure drop data.
Date: June 24, 2004
Creator: POIRIER, MICHAEL
Partner: UNT Libraries Government Documents Department

An evaluation of three commercially available technologies forreal-time measurement of rates of outdoor airflow into HVAC systems

Description: During the last few years, new technologies have been introduced for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurements technologies has not previously been published. This document describes a test system and protocols developed for a controlled evaluation of these measurement technologies. The results of tests of three commercially available measurement technologies are also summarized. The test system and protocol were judged practical and very useful. The three commercially available measurement technologies should provide reasonably, e.g., 20%, accurate measurements of OA flow rates as long as air velocities are maintained high enough to produce accurately measurable pressure signals. In HVAC systems with economizer controls, to maintain the required air velocities the OA intake will need to be divided into two sections in parallel, each with a separate OA damper. All of the measurement devices had pressure drops that are likely to be judged acceptable. The influence of wind on the accuracy of these measurement technologies still needs to be evaluated.
Date: October 28, 2004
Creator: Fisk, William J.; Faulkner, David & Sullivan, Douglas P.
Partner: UNT Libraries Government Documents Department

METAL MEDIA FILTERS, AG-1 SECTION FI

Description: One application of metal media filters is in various nuclear air cleaning processes including applications for protecting workers, the public and the environment from hazardous and radioactive particles. To support this application the development of the ASME AG-1 FI Standard on Metal Media has been under way for more than ten years. Development of the proposed section has required resolving several difficult issues associated with operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality acceptance testing. Performance characteristics of metal media are dramatically different than the glass fiber media with respect to parameters like differential pressures, operating temperatures, media strength, etc. These differences make existing data for a glass fiber media inadequate for qualifying a metal media filter for AG-1. In the past much work has been conducted on metal media filters at facilities such as Lawrence Livermore National Laboratory (LLNL) and Savannah River National Laboratory (SRNL) to qualify the media as High Efficiency Particulate Air (HEPA) Filters. Particle retention testing has been conducted at Oak Ridge Filter Test Facility and at Air Techniques International (ATI) to prove that the metal media meets or exceeds the 99.97% particle retention required for a HEPA Filter. Even with his testing, data was lacking to complete an AG-1 FI Standard on metal media. With funding secured by Mississippi State University (MSU) from National Nuclear Security Administration (NNSA), a research test stand is being designed and fabricated at MSU's Institute for Clean Energy Technology (ICET) Facility to obtain qualification data on metal media. This in turn will support required data needed for the FI Standard. The paper will discuss in detail how the test stand at MSU will obtain the necessary data to complete the FI Standard.
Date: May 23, 2012
Creator: Adamson, D.
Partner: UNT Libraries Government Documents Department

CONDITIONS LEADING TO SUDDEN RELEASE OF MAGMA PRESSURE

Description: Buildup of magmatic pressures in a volcanic system can arise from a variety of mechanisms. Numerical models of the response of volcanic structures to buildup of pressures in magma in dikes and conduits provide estimates of the pressures needed to reopen blocked volcanic vents. They also can bound the magnitude of sudden pressure drops in a dike or conduit due to such reopening. Three scenarios are considered: a dike that is sheared off by covolcanic normal faulting, a scoria cone over a conduit that is blocked by in-falling scoria and some length of solidified magma, and a lava flow whose feed has partially solidified due to an interruption of magma supply from below. For faulting, it is found that magma would be able to follow the fault to a new surface eruption. A small increase in magma pressure over that needed to maintain flow prior to faulting is required to open the new path, and the magma pressure needed to maintain flow is lower but still greater than for the original dike. The magma pressure needed to overcome the other types of blockages depends on the details of the blockage. For example, for a scoria cone, it depends on the depth of the slumped scoria and on the depth to which the magma has solidified in the conduit. In general, failure of the blockage is expected to occur by radial hydrofracture just below the blocked length of conduit at magma pressures of 10 MPa or less, resulting in radial dikes. However, this conclusion is based on the assumption that the fluid magma has direct access to the rock surrounding the conduit. If, on the other hand, there is a zone of solidified basalt, still hot enough to deform plastically, surrounding the molten magma in the conduit, this could prevent breakout ...
Date: August 26, 2005
Creator: Damjanac, B. & Gaffney, E.S.
Partner: UNT Libraries Government Documents Department