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At least 109 records · Page 6

Pollution Control Device

BHA Group Inc.'s PrecipTech Power Guard SQ-200 automatic voltage controller, combined with a remote computer, is an automatic management system for smoke-cleaning precipitators. It is the second generation of the SQ 100 developed at Langley Research Center, and was commercialized by two NASA employees. An electrostatic precipitator cleans the smoke by removing particulate matter from smokestack gases before gases are expelled into the atmosphere. Smokestack gas is passed through a precipitator chamber and exposed to an electrostatic field; dust particles in the gas become electrically charged, migrate to collection surfaces and are "captured." Developed under a NASA program seeking a way to dispose refuse, the system monitors sparking, automatically adjusts to changes in operating conditions and does not require a skilled operator.

Source record↗

Simple control device senses solar position

The amount of solar radiation incident on a specially prepared bimetallic strip is simply and reliably controlled by a light valve. This device is valuable for systems requiring temperature regulation.

Lonborg, J. O.↗

Thumb-actuated control device

Rotary potentiometer device on the spoke of an aircraft steering wheel provides servo control of certain flight characteristics with no visual attention and a minimum of operational movement.

Hadland, W. O.↗

Spin-rate control device

Innovation eliminates need for driver, sensor, and interconnecting logic circuits. Device combines simplicity of fixed-fin concept with precise rate control provided by active flight control system.

Nolte, L. J.↗

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate. The results indicated that the adjustable cowling flap and the bottom opening with adjustable flap were about equally effective on the basis of pressure drop obtainable and that both were more effective means of increasing the pressure drop through the cowling than the adjustable-length skirt. At conditions of equal cooling-air flow, the net efficiency obtained with the adjustable cowling flaps and the adjustable-length cowling skirt was about 1% greater than the net efficiency obtained with the bottom opening with adjustable flap.

McHugh, James G.↗

Investigations of electret as a contamination control device

Thermoelectrets of polymers with stable surface charge on either side have been found to attract ions and charged particles to their surfaces. To assess their applicability to the control of atmospheric contamination, polytetraethylene (teflon) electrets are exposed to vapors coming from volatile mixtures over periods up to 90 min. Use is made of mass spectrometry for the analysis of teflon electret characteristics. It is found that even small quantities of the liquids in the mixture gives its characteristic mass spectra and that the peak height represents a measure for the quantity of the material collected over the electret surface, with the collected quantity being proportional to the duration of exposure.

Pillai, P. K. C.↗

Application of Micro-ramp Flow Control Devices to an Oblique Shock Interaction

Tests are planned in the 15cm x 15cm supersonic wind tunnel at NASA Glenn to demonstrate the applicability of micro-ramp flow control to the management of shock wave boundary layer interactions. These tests will be used as a database for computational fluid dynamics (CFD) validation and Design of Experiments (DoE) design information. Micro-ramps show potential for mechanically simple and fail-safe boundary layer control.

Hirt, Stefanie↗

Present Status of Lateral-Control Devices for use with Split Flaps, Special Report

The increased use of split flaps for the dual purpose of reducing the landing speed and shortening the landing glide of airplanes has established as acute the problem of obtaining satisfactory lateral control to be used in conjunction with the flaps with out the sacrifice of any of the effectiveness of the flaps. A large amount of work is being done on this problem by various organizations and individuals. Several of the devices developed seem usable, some of them unquestionably so. The present paper attempts to summarize the most promising results obtained to date. Topics covered include ordinary ailerons, external ailerons, floating ailerons, upper-surface ailerons, and spoilers. Although the external ailerons above the trailing edge of the wing and the spoilers at the rear of the wing appear quite promising, it would seem that probably the most satisfactory immediate solution of the problem, including the obtaining of light and smoothly graduated control forces, would in most cases be obtained by the use of the arrangement in which the flap is retracted ahead of ordinary narrow-chord ailerons and is deflected to the rear as well as downward when in use.

Weick, Fred E.↗

Development of Thermal Control Devices for Extreme Lunar Environments at Marshall Space Flight Center

NASA’s return to the moon brings many challenges, including issues with sustainable survival on the Lunar surface. One of the key challenges with sustainability is designing adequate thermal control systems that allow for surface systems to survive both during the day and the Lunar Night. The extreme thermal environments on the Lunar surface are a challenging design space for thermal engineers. At equatorial regions, the Lunar noon can be very hot, requiring systems with high heat rejection to the environment. At polar regions, such as those targeted by the return to the moon, the Lunar night temperatures plummet to -200 degrees Celsius or lower. Such temperatures are formidable and require specialized thermal control systems to allow surface assets to surface the long night.

Will Johnson↗

Investigation of Vortex Flaps and Other Flow Control Devices on Generic High-Speed Civil Transport Planforms

A parametric cranked delta planform study has been conducted in the Langley 14- by 22-Foot Subsonic Tunnel with the following objectives: (1) to evaluate the vortex flap design methodology for cranked delta wings, (2) to determine the influence of leading-edge sweep and the outboard wing on vortex flap effectiveness, (3) to evaluate novel flow control concepts, and (4) to validate unstructured grid Euler computer code predictions with modeled vortex and trailing-edge flaps. Two families of cranked delta planforms were investigated. One family had constant aspect ratio, while the other had a constant nondimensional semispan location of the leading-edge break. The inboard leading-edge sweep of the planforms was varied between 68 deg., 71 deg., and 74 deg., while outboard leading-edge sweep was varied between 48 deg. and 61 deg. Vortex flaps for the different planforms were designed by an analytical vortex flap design method. The results indicate that the effectiveness of the vortex flaps was only slightly influenced by the variations in the parametric planforms. The unstructured grid Euler computer code was successfully used to model the configurations with vortex flaps. The vortex trap concept was successfully demonstrated.

Kjerstad, Kevin J.↗

Wind-tunnel of three lateral-control devices in combination with a full-span slotted flap on an NACA 23012 airfoil

A large-chord NACA 23012 airfoil was tested. The airfoil extended completely across the test section, and two-dimensional flow was approximated. The model was fitted with a full-span slotted flap having a chord 25.66 percent of the airfoil chord. The ailerons investigated extended over the entire span and each had a chord 10 percent of the airfoil chord. The types of ailerons tested were: retractable ailerons, slot-lip ailerons using the lip of the slot for ailerons, and plain ailerons on the trailing edge of the slotted flap. The data are presented in the form of curves of section lift, drag, and pitching-moment coefficients for the airfoil with flap deflected but with ailerons neutral, and of rolling-moment, yawing-moment, and hinge-moment coefficients calculated for a rectangular wing of aspect ratio 6 with a semi-span aileron and a full-span flap. For the ailerons investigated the data indicate that, from considerations of rolling and yawing moments produced and of stick forces desired, the retractable aileron is the most satisfactory means of lateral control for use with a full-span slotted flap.

Wenzinger, Carl J↗