Articles with tag: "engine inlet"

(Note: figures do not appear in the summaries below)

  1. NACA-RM-E57G09

    "the contour plots indicate that cowl-lip disturbances are the more controlling factor"

    "Total Pressure Distortion and Recovery of Supersonic Nose Inlet with Conical Centerbody in Subsonic Icing Conditions" 1

    Figure 9. Maps of local to free-stream total-pressure ratio at compressor face and photographs of iced model. Angle of attack, 0°.

    Abstract

    Ice was formed on a full-scale unheated supersonic nose inlet in the NACA Lewis icing tunnel to determine its effect on compressor-face total-pressure distortion and recovery. Inlet angle of attack was varied from 0° to 12°, free-stream Mach number from 0.17 to 0.28, and compressor-face Mach number from 0.10 to 0.47. Icing-cloud liquid-water content was varied from 0.65 to 1.8 grams per cubic meter at free-stream static air temperatures of 15° and 0° F.

    The addition of ice to the inlet components increased total-pressure- distortion levels and decreased recovery values compared with clear-air results, the losses increasing with time in ice. The combination of glaze ice, high corrected weight flow, and high angle of …

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  2. NACA-TN-4093

    "Rotational speeds up to 1200 rpm had no apparent effect on the heat-transfer characteristics of the spinner"

    "Investigation of Heat Transfer from a Stationary and Rotating Conical Forebody"

    Figure 5. Variation of surface temperature, effective heater input power density, and convective heat-transfer coefficient for stationary spinner with uniform heat input. Free-stream velocity, 282 feet per second; angle of attack, 0°; average free-stream total temperature, -1° F.

    Abstract

    The convective heat transfer from the surface of a conical forebody having a hemispherical nose, an included angle of approximately 30°, and a maximum diameter of 18.9 inches was investigated in a wind tunnel for both stationary and rotating operation. The range of test conditions included free-stream velocities up to 400 feet per second, rotational speeds up to 1200 rpm, and. angles of attack of 0° and 6°. Both a uniform surface temperature and a uniform heater input power density were used.

    The Nusselt-Reynold's number relations provided good correlation of the heat-transfer data for the complete operating range at 0° angle of attack with and without spinner rotation, and for 6° angle of attack with rotation. Rotational speeds up to …

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  3. NACA-TN-3837

    "Many aircraft components are essentially simple bodies of revolution; examples of these are radomes, body noses, engine accessory housings, and the large spinners of turboprop engines"

    "Investigation of Heat Transfer from a Stationary and Rotating Ellipsoidal Forebody of Fineness Ratio 3" 1

    Figure 6. Distribution of surface temperature, heat input, and convective heat-transfer coefficient for stationary Spinner with uniform surface temperature. Free-stream velocity, 152 knots; air total temperature, 0° F; angle of attack, 0°.

    Abstract

    The convective heat transfer from the surface of an ellipsoidal fore-body of fineness ratio 3 and 20-inch maximum diameter was investigated in clear air for both stationary and rotating operation over a range of conditions including air speeds up to 240 knots, rotational speeds up to 1200 rpm, and angles of attack of 0°, 3°, and 6°. The results are presented in the form of heat-transfer coefficients and the correlation of Nusselt and Reynolds numbers. Both a uniform surface temperature and a uniform input heater density distribution were used.

    The experimental results agree well with theoretical predictions for uniform surface temperature distribution. Complete agreement was not obtained …

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  4. NACA-RM-E51B12

    "Serious icing of a turbojet-engine installation may render the engine inoperative in a matter of minutes."

    "NACA Investigations of Icing-Protection Systems for Turbojet-Engine Installations" 1

    Figure 6. Typical double-peaked glaze-ice formation on inlet lips of turbojet-engine installation.

    Abstract

    Investigations have been made in flight and in wind tunnels tc determine which components of turbojet installations are most critical in icing conditions, and to evaluate several methods of icing protection. From these studies, the requirements necessary for adequate icing protection and the consequent penalties on engine performance can be estimated.

    Because investigations have indicated that the compressor-inlet screen constitutes the greatest icing hazard and is difficult to protect, complete removal or retraction of the screen upon encountering an icing condition is recommended. In the absence of the screen, the inlet guide vanes of an axial-flow-type turbojet engine constitute the greatest danger to engine operation in an icing condition; a centrifugal- type engine, on the other hand, is relatively unsusceptible to icing once the …

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  5. NACA-RM-E50H29

    "Experience has shown that ... the inlet guide vanes of an axial-flow turbojet engine constitute the most critical component to be protected from icing"

    "Investigation of Power Requirements for Ice Prevention and Cyclical De-Icing of Inlet Guide Vanes with Internal Electric Heaters" 1

    Figure 20. Typical ice formatione on inlet guide vane for various icing conditions, Air velocity, approximately 400 feet per second.

    Abstract

    An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection.
    The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating. Heat-on periods in the order of 10 seconds with a cycle ratio of about 1:7 …

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  6. NACA-RM-E50I08

    "Ice formations ... may have the following effects, which when combined may become serious enough to necessitate a shutdown of the engine: reduced engine thrust, increased,fuel consumption, and increased tail-pipe temperature."

    "Icing Characteristics and Anti-Icing Heat Requirements for Hollow and Internally Modified Gas-Heated Inlet Guide Vanes" 1

    Figure 8. Typical icing with submarginal heating.

    Abstract

    A two-dimensional inlet-guide-vane cascade was investigated to determine the effects of ice formations on the pressure losses across the guide vanes and to evaluate the heated gas flow and temperature required to prevent icing at various conditions. A gas flow of approximately 0.4 percent of the inlet-air flow was necessary for anti-icing a hollow guide-vane stage at an inlet-gas temperature of 500° F under the following icing conditions: air velocity, 280 miles per hour; water content, 0.9 gram per cubic meter; and inlet-air static temperature, 0° F. Also presented are the anti-icing gas flows required with modifications of the hollow …

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  7. NACA-TN-2126

    "Use of the hot-gas method of anti-icing has been restricted ... because of difficulty in controlling the rate of heat dissipation"

    "Improvements in Heat Transfer for Anti-Icing of Gas-Heated Airfoils with Internal Fins and Partitions" 1

    Figure 3. Detail of three case-heated airfoil sections.

    Abstract

    The effect of modifying the gas passage of hollow metal airfoils by the additIon of internal fins and partitions was experimentally investigated and comparisons were made among a basic unfinned airfoil section and two airfoil designs having metal fins attached at the leading edge of the internal gas passage. An analysis considering the effects of heat conduction in the airfoil metal was made to determine the internal modification effectiveness that may be obtained in gas-heated components, such as turbojet-inlet guide vanes, support struts, hollow propeller blades, arid. thin wings.

    Over a wide range of heated-gas flow and tunnel-air velocity, the increase in surface-heating rates with internal fin was marked (up to 3.5 times …

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  8. NACA-RM-E8FO1a

    "The engine was satisfactorily accelerated to take-off power after approximately 45 minutes in the icing condition"

    "Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition" 1

    Figure 4a. Ice formation on engine cowling after icing flight. Side view, the ice is about 4 inch thick in the inlet leading edge.

    Abstract

    An investigation has been conducted In natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. One flight was made in an icing condition in which the liquid.-water content varied from 0.077 to 0.490 gram per cubic meter and the average droplet size varied from 5.4 to 12.1 microns. During a period of 60 minutes in icing, at an engine speed of 11,000 rpm, the tail-pipe temperature increased from 8650 to 9650 F and the jet thrust decreased from 1950 to 1700 pounds. Near the end of the icing period, the engine was satisfactorily accelerated to take-off power.

    Discussion

    As this publication is brief …

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  9. NACA-RM-E8C18

    "Ice formations penetrated to the second-stage rotor blades"

    "Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine" 1

    Figure 2. Close-up of axial-flow turbojet engine mounted on test airplane.

    Abstract

    A flight investigation is being conducted. in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. One flight was made in icing conditions in which the icing rate varied from 5.1 to 2.1 inches per hour. During a period of 45 minutes in icing, the tail-pipe temperature increased from 761° to 1065° F and the jet thrust decreased from 1234 to 910 pounds. Ice penetrated to the second-stage stator blades. No general conclusions can be reached from these data because the icing condition was relatively light.

    Discussion

    As this publication is brief (18 pages, with 12 of those photos or blank), it is reproduced nearly in its entirety herein.

    The jet engine inlet in this case did not have …

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  10. NACA-TN-1246

    "The icing of the unprotected installation presents a serious operational problem"

    "Wind-Tunnel Investigation of Icing of an Engine Cooling-Fan Installation" 1

    Figure 9. Ice formations on the cooling-fan installation after 10-minute run at air temperature of 14 F, liquid-water content of 0.5 gram per cubic meter, and fan speed of 1060 rpm.

    Abstract

    An investigation was made of the icing characteristics and means of ice protection of a typIcal radial-engine cooling-fan installation, The investigation was made at various icing and performance conditions in the icing research tunnel of the NACA Cleveland laboratory.

    The icing of the unprotected cooling-fan installation was found to present a serious operational problem. Reduction in air flow below the minimum value required for engine cooling occurred within 2 minutes and complete stoppage of the cooling-air flow through the fan assembly occurred in as little as 5 minutes under normal icing conditions.

    Steam de-icing was found to be effective for the cowling lip and inlet duct. Alcohol de-icing of the fan blades and stator vanes was found to be unsatisfactory. Electrical heat de-icing of the fan blades was …

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  11. Engine Inlet Icing

    "The desirability for all-weather operation of turbojet aircraft has necessitated extensive research on methods of icing protection for the various engine components"

    Figure 3b. Ice formation on axial-flow turbojet engine. Side view of ice formation on engine inlet.
    From NACA-RM-E8C18.

    Discussion

    Publications taken largely from The Historical Selected Bibliography of NACA-NASA Icing Publications, "Turbine-Type Engine and Inlet Icing Studies" section are reviewed here.

    Reviews

    NACA-TN-1246 "Wind-Tunnel Investigation of Icing of an Engine Cooling-Fan Installation"

    • "The icing of the unprotected installation presents a serious operational problem"

    NACA-RM-E8C18 "Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine"

    • "Ice formations penetrated to the second-stage rotor blades"

    NACA-RM-E8FO1a "Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition"

    • "The engine was satisfactorily accelerated to take-off power after approximately 45 minutes in the icing condition"

    NACA-TN-2126 "Improvements in Heat Transfer for Anti-Icing of Gas-Heated Airfoils with Internal Fins and Partitions"

    • "Use of the hot-gas method of anti-icing has been restricted ... because of difficulty in controlling the …
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