Models for Generating and Processing of Signals of the Panoramic Sensor of Aerodynamic Angle and True Airspeed

The importance of information about the true airspeed and aerodynamic angles of aircraft and replenishment of arsenal of their measuring means with only electronic design scheme, low weight and cost, providing a panoramic measurement of the gliding angle is noted. It is shown that traditional measuring means of true airspeed of AP, which implement the aerodynamic and vane measuring methods of parameters of incoming air flow, using receivers and sensors distributed over the fuselage, have a complex design, significant weight and cost, and limited ranges of measuring aerodynamic angles, which limits their use on small-sized aircraft plane. The integrated sensor of aerodynamic angle and true airspeed, which implements a vortex method for measuring the parameters of incoming air flow, is considered. A single fixed flow receiver simplifies the design, and the time-frequency primary informative signals reduce the errors of instrumentation channel. The limited range of measurement of the gliding angle limits the use of the sensor on small AP. The integrated sensor of aerodynamic angle and true airspeed, which implements the ion-mark method for measuring the parameters of incoming air flow, is considered. The sensor provides a panoramic measurement of aerodynamic angle using receivers distributed in the measurement plane. But the multichannel measuring circuit significantly complicates the design, increases the weight and cost of the sensor, which limits its use on small-sized aircraft plane. The functional scheme of the original panoramic purely electronic sensor of the aerodynamic angle and true airspeed with one fixed receiver of the incoming air flow and ultrasonic instrumentation channels is revealed. Analytical models of the formation, processing and determination of the aerodynamic angle and true airspeed using frequency, time-pulse and phase informative signals are obtained. The analysis of the variants of used informative signals determines the prospects of using of the panoramic sensor with frequency informative signals on small-sized aircraft plane, in which there are no methodological errors from the influence of the ambient temperature when changing the flight altitude.

Estimation of Aerodynamic Load on Radome Structure Mounted on Top of a Surveillance Aircraft

The design and development of radome external structure, requires aerodynamic forces acting on it and its distribution. This paper discusses the wind tunnel studies carried out for estimating the incremental effects due to the installation of large ellipsoidal radome along with the support structure pylons on the dorsal side of the fuselage. Effect of locations of radome at 36 m and 31.5 m from the nose of the fuselage is discussed. Further using the scan-valve pressure transducer, the pressure distribution on the radome measured at different aerodynamic angles required for the structural design of radome structure is also brought out. Flow visualization study which are useful for qualitative check for the effect of installation of the radome with support structure on the effectiveness of the empennage is attempted.

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

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.