scholarly journals INTEGRATION OF THE MEASURED ALTITUDE-SPEED PERFORMANCES IN THE SYSTEM

2021 ◽  
Vol 2 (64) ◽  
pp. 18-22
Author(s):  
Artyom I. Ponomarev ◽  
◽  
Mikhail Y. Sorokin ◽  
Keyword(s):  
Air Temperature ◽  
Angle Of Attack ◽  
Data System ◽  
Operating Principle ◽  
Flight Parameters ◽  
Movement Parameters ◽  
Aerodynamic Angle ◽  
Onboard Equipment

The air data system used by modern aircrafts is a soft hardware designed to measure, compute, and display the altitude-speed performances as well as other parameters such as air temperature, angles of attack and slip; and to provide to aircrew and consumers (various on-board systems) with this information. The speed and altitude are one of the most important flight parameters of an aircraft. The operating principle of modern onboard equipment for measuring the aircraft movement parameters while in flight is based on an aerometric method. This article deals with a method for increasing the accuracy and the reliability of aerodynamic angle-of-attack measurements.

Effects of Pressure Ports Layout on Angle of Attack and Sideslip Estimation in the Flush Air Data System

2011 ◽  
Vol 383-390 ◽  
pp. 2996-3000
Author(s):  
Fu Li ◽  
Zhen Luo
Keyword(s):  
Least Squares ◽  
Angle Of Attack ◽  
Inertial Navigation ◽  
Nonlinear Least Squares ◽  
High Accuracy ◽  
Data System ◽  
Evaluation Function ◽  
Theory Evaluation ◽  
Sideslip Estimation ◽  
Radiation Type

Flush air data system (FADS) have been successfully used on the nose tip of large manned/unmanned air vehicles instead of a traditional noseboom air data system. In order to integrate FADS with strapdown inertial navigation, high accuracy of angle of attack and sideslip is required. The estimated accuracy of angle of attack and sideslip in three types of FADS, which have different pressure ports layout, is compared using the nonlinear least squares theory. Evaluation function is provided to evaluate the accuracy of angle of attack and sideslip in different pressure ports layout. The results show that more sensors and radiation-type can provide high accuracy.

scholarly journals 2D Numerical Simulation Study of Airfoil Performance

2021 ◽  
Author(s):  
Nasser Shelil
Keyword(s):  
Experimental Data ◽  
Wind Tunnel ◽  
Air Temperature ◽  
Wind Turbines ◽  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Turbulence Models ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Ansys Fluent

Abstract. The aerodynamic characteristics of DTU-LN221 airfoil is studied. ANSYS Fluent is used to simulate the airfoil performance with seven different turbulence models. The simulation results for the airfoil with different turbulence models are compared with the wind tunnel experimental data performed under the same operating conditions. It is found that there is a good agreement between the computational fluid dynamics (CFD) predicted aerodynamic force coefficients with wind tunnel experimental data especially with angle of attack between −5° to 10°. RSM is chosen to investigate the flow field structure and the surface pressure coefficients under different angle of attack between −5° to 10°. Also the effect of changing air temperature, velocity and turbulence intensity on lift and drag coefficients/forces are examined. The results show that it is recommended to operate the wind turbines airfoil at low air temperature and high velocity to enhance the performance of the wind turbines.

Implicit LES Simulations of a Flapping Wing in Forward Flight

2013 ◽  
Author(s):  
Raymond E. Gordnier ◽  
Luciano Demasi
Keyword(s):  
Reynolds Number ◽  
Angle Of Attack ◽  
Micro Air Vehicles ◽  
Navier Stokes ◽  
Forward Flight ◽  
Freestream Velocity ◽  
Flapping Motion ◽  
Wing Motion ◽  
Low Reynolds Number Flows ◽  
Aerodynamic Angle

Computations of an aspect ratio 3.5 flat plate wing in flapping forward flight are performed. A high-order implicit LES approach is employed to compute the mixed laminar/transitional/turbulent flowfields present for the low Reynolds number flows associated with micro air vehicles. The ILES approach is implemented by exploiting the properties of a well validated, robust, sixth-order Navier-Stokes solver. The analyzed kinematics are a flapping motion described by an anti-clockwise 8 cycle. A Reynolds number based on the freestream velocity of 1250 is prescribed. A detailed description of the dynamic vortex system engendered by the unsteady flapping motion is given and related to the development of lift and thrust during the flapping cycle. Effective angle of attack, which results from the wing motion, and its interplay with the aerodynamic angle of attack play a key role in determining the flow structure and forces produced.

scholarly journals An unusual Barothermometer

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Dario Camuffo
Keyword(s):  
19Th Century ◽  
Air Temperature ◽  
Barometric Pressure ◽  
Measuring Method ◽  
Operating Principle ◽  
Weather Changes ◽  
Instructions For Use ◽  
The 19Th Century

An unusual instrument, named “Barothermometer”, belonging to the collection of Villa Vigoni, on the Como Lake, Italy, is analysed. The instrument is composed of a U-shaped thermoscope and a spirit thermometer. Both instruments have their tubes placed side-by-side on the same frame and use the same scale. It measures the air temperature and the tendency of the barometric pressure to predict weather changes. A study is made to clarify the operating principle and produce the instructions for use. The development of the ideas to which the instrument has been inspired follows a tree starting with the Galileo’s thermoscope, the Amontons air thermometer and finally the Adie sympiesometer. The measuring method is typical of the first half of the 19th century, but the construction details in aluminium, the fonts used in the printed instructions and the colour fading suggest that the instrument was built around 1930-40.  

Features of Construction and Analysis of Static Accuracy of the Vortex Air Data System of Subsonic Aircraft

2019 ◽  
Vol 20 (7) ◽  
pp. 443-448
Author(s):  
V. M. Soldatkin ◽  
E. S. Efremova
Keyword(s):  
Data System ◽  
Absolute Pressure ◽  
Data Systems ◽  
Air Velocity ◽  
Aerodynamic Angles ◽  
Vortex Sensor ◽  
Informative Signals ◽  
Aerodynamic Angle ◽  
Prospects Of Application ◽  
Streamlined Surface

The importance of information is noted and the defects of traditional air data systems are described, implementing aerometric, aerodynamic and directional methods using straddled in the fuselage of the air pressure receiver, temperature braking receivers, sensors aerodynamic angles of attack and slip. The features of construction and advantages of the original vortex air data system with one stationary receiver of primary information and frequency-time primary informative signals based on the original vortex sensor of aerodynamic angle and true air velocity with a hole-receiver of static pressure on its streamlined surface associated with the absolute pressure sensor with frequency output are considered. It is noted that according to the results of calculations, the instrumental static errors of the measuring channels of the vortex air data system are close in magnitude to the instrumental errors of traditional air data systems. The reasons are considered, mathematical models and calculated values of methodical static errors of measuring channels of vortex air data system which testify to prospects of application of system on subsonic aircraft are received.

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