Optical Atmospheric Air-Speed Sensor for EDL Operations

2020 ◽  
Author(s):  
Elie R. Salameh ◽  
Jaime Da Silva ◽  
M. Volkan Otugen ◽  
Dominique Fourguette
Keyword(s):  
Atmospheric Air ◽  
Speed Sensor ◽  
Air Speed

Computation and Analysis of Frost Formation on Ground Aircraft

2012 ◽  
Vol 490-495 ◽  
pp. 166-170
Author(s):  
Li Wen Wang ◽  
Dan Dan Xu
Keyword(s):  
Water Vapor ◽  
Theoretical Model ◽  
Surface Temperature ◽  
Air Temperature ◽  
Temperature Decrease ◽  
Air Velocity ◽  
Frost Formation ◽  
Atmospheric Air ◽  
Air Speed ◽  
The Stability

Aircraft ground icing can result in decreasing the stability of the aircraft at or shortly after take off.. A theoretical model for frost formation by water vapor on aircraft in atmospheric air has been presented in this study. Frost surface temperature and frost thickness can be obtained by the model. Effects of aircraft surface temperatures and air conditions, such as aircraft surface temperature, air temperature and air velocity on the frost surface temperature and frost thickness can be evaluated by using this model. It revealed that the surface temperature increases with the surface temperature, the air speed and air temperature. The frost thickness increases with the air speed and the air temperature, decrease with the surface temperature.

scholarly journals Thermodynamic correction of particle concentrations measured by underwing probes on fast flying aircraft

2015 ◽  
Vol 8 (12) ◽  
pp. 13423-13469 ◽  
Author(s):  
R. Weigel ◽  
P. Spichtinger ◽  
C. Mahnke ◽  
M. Klingebiel ◽  
A. Afchine ◽  
...  
Keyword(s):  
Particle Concentration ◽  
Sample Volume ◽  
Ambient Conditions ◽  
Speed Sensor ◽  
Particle Penetration ◽  
Research Aircraft ◽  
Air Sample ◽  
Air Speed ◽  
Particle Imaging ◽  
Measured Particle

Abstract. Particle concentration measurements with underwing probes on aircraft are impacted by air compression upstream of the instrument body as a function of flight velocity. In particular for fast-flying aircraft the necessity arises to account for compression of the air sample volume. Hence, a correction procedure is needed to invert measured particle number concentrations to ambient conditions that is commonly applicable for different instruments to gain comparable results. In the compression region where the detection of particles occurs (i.e. under factual measurement conditions), pressure and temperature of the air sample are increased compared to ambient (undisturbed) conditions in certain distance away from the aircraft. Conventional procedures for scaling the measured number densities to ambient conditions presume that the particle penetration speed through the instruments' detection area equals the aircraft speed (True Air Speed, TAS). However, particle imaging instruments equipped with pitot-tubes measuring the Probe Air Speed (PAS) of each underwing probe reveal PAS values systematically below those of the TAS. We conclude that the deviation between PAS and TAS is mainly caused by the compression of the probed air sample. From measurements during two missions in 2014 with the German Gulfstream G-550 (HALO – High Altitude LOng range) research aircraft we develop a procedure to correct the measured particle concentration to ambient conditions using a thermodynamic approach. With the provided equation the corresponding concentration correction factor ξ is applicable to the high frequency measurements of each underwing probe which is equipped with its own air speed sensor (e.g. a pitot-tube). ξ-values of 1 to 0.85 are calculated for air speeds (i.e. TAS) between 60 and 260 m s−1. From HALO data it is found that ξ does not significantly vary between the different deployed instruments. Thus, for the current HALO underwing probe configuration a parameterisation of ξ as a function of TAS is provided for instances if PAS measurements are lacking. The ξ-correction yields higher ambient particle concentration by about 15–25 % compared to conventional procedures – an improvement which can be considered as significant for many research applications. The calculated ξ-values are specifically related to the considered HALO underwing probe arrangement and may differ for other aircraft or instrument geometries. Moreover, the ξ-correction may not cover all impacts originating from high flight velocities and from interferences between the instruments and, e.g., the aircraft wings and/or fuselage. Consequently, it is important that PAS (as a function of TAS) is individually measured by each probe deployed underneath the wings of a fast-flying aircraft.

AIR SPEED SENSOR FOR MEASURING NATURAL CONVECTION IN DRYERS AND STOREHOUSES

2005 ◽  
Vol 38 (1) ◽  
pp. 57-62
Author(s):  
I. Seres ◽  
L. Kocsis ◽  
K. Gottschalk ◽  
I. Farkas
Keyword(s):  
Natural Convection ◽  
Speed Sensor ◽  
Air Speed

ORIENTATION OF AEDES AEGYPTI IN VERTICAL AIR CURRENTS

1967 ◽  
Vol 99 (3) ◽  
pp. 303-308 ◽  
Author(s):  
P. N. Daykin
Keyword(s):  
Aedes Aegypti ◽  
Air Flow ◽  
Sensory Information ◽  
Vertical Movement ◽  
Stripe Pattern ◽  
Vertical Movements ◽  
Speed Sensor ◽  
Air Stream ◽  
Cybernetic System ◽  
Air Speed

AbstractThe orientation of Aedes aegypti in an upward or downward vertical air current was studied. The vertical movements of A. aegypti which have been activated by CO2 are always against the air flow and toward the inlet end, where the insects alight and probe. With sufficient illumination A. aegypti locate an invisible artificial host whether it is at the top with air moving down or at the bottom with air moving up. They do not attempt to locate a visible, black, artificial host placed downstream. Body attitude is similar in upward or downward air flow. The mosquitoes follow the vertical movement of a surrounding spiral stripe pattern, whether stripe movement is upward or downward, whether air is still or moving vertically with or against the stripes. They will not fly against stripe movement to reach an upstream host, real or artificial. Repellent vapor destroys the upstream orientation when air flow is vertical but not when the flow is horizontal. The stripe-following action is not affected by repellent. The experiments indicate that A. aegypti possesses a vertical-air-speed sensor, of a mechanical type, to direct movement up or down in a vertical air stream. The cybernetic system must be complex and requires cooperative use of mechanical and optical sensory information channels. The initial action of repellent vapor appears to be peripheral rather than central to the nervous system, and to affect only the mechano-, chemo-, and thermo-receptors.

A True Air Speed Sensor for Miniature Unmanned Aircraft

1982 ◽  
Vol 1 (1) ◽  
pp. 44-45
Author(s):  
J.A.C. Beattie
Keyword(s):  
Thick Film ◽  
Vortex Shedding ◽  
Unmanned Aircraft ◽  
Digital Output ◽  
Speed Sensor ◽  
Air Speed ◽  
Laboratory Prototype

This paper describes the development of a laboratory prototype true air speed sensor for use on unmanned aircraft. The sensor works on vortex shedding principles and has a digital output. The vortices are sensed by thick film thermistor elements that are non‐critical in the signal circuitry.

Influence of meteorological factors on the secondary contamination of atmospheric air by formaldehyde ( on example of city of Kyiv).

2019 ◽  
pp. 75-86
Author(s):  
Irina Klimova ◽  
Rostyslav Sipakov
Keyword(s):  
Cross Correlation ◽  
Meteorological Factors ◽  
Climatic Factors ◽  
Nature Protection ◽  
Protection Measures ◽  
Atmospheric Air ◽  
Motor Transport ◽  
Basic Source ◽  
Air Speed ◽  
Secondary Contamination

Many authors on the basis of researches give information that a motor transport is the basic source of contamination of atmospheric air of cities of Ukraine. This work touches the estimation of level and dynamics of contamination of m. Kyiv extrass from a motor transport and influence of meteorological factors of locality on the degree of atmospheric contamination (including secondary one as a result of actinic transformations). Authors set connection between the components of SO, Nox, CHOH and ambient temperature, on the basis of analysis of the last five years of statistical information of basic components contaminations from a motor transport, which take part in formation of actinic transformations. Authors found out close cross-correlation connection between the molecules of Nox, CHOH and average monthly values of temperature on the basis of analysis of these monitoring supervisions. Also there were investigational processes of formation of molecules of SNON depending on other climatic factors of city of Kyiv, namely: to humidity of air, speed of wind and index of acidity of atmosphere (pH). It is well-proven that formation of formaldehyde in mid air above motor transport ways the degree of acidificationof atmospheric fallouts influences mediated. However have direct cross-correlation connection of relative humidity of air and speed of wind. Temperature terms play a key role in forming of the secondary contamination formaldehyde above motor transport overpasses and he takes into account other climatic factors of locality mediated. Speed of reaction of transformation of hydrocarbons in formaldehyde at neutral meteorological terms is considered on the example of motor-car upshot of the Darnicka square. The decision of equalization of speed of transformation of extrass of hydrocarbons is found in formaldehyde by the decision of equalization of Arreniusa. This method can be applied for other cities of Ukraine. The conducted researches will allow to promote ecological strength security on the urbanized territories by the improvement of questions of acceptance of administrative decisions at building and reconstruction of motor-car overpasses of city, and also at forming of strategic plans of ecological development of city and setting of nature protection measures.

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