A Boundary Layer Electron Density Diagnosis System of Hypersonic Vehicle Based on High Frequency Electrostatic Probe

Abstract

The invention discloses a hypersonic aircraft boundary layer electron density diagnosis system based on a high-frequency electrostatic probe, which includes a signal modulation unit, a high-voltage power amplifier unit, a data acquisition and processing unit, a high-enthalpy shock tunnel, a probe and a model unit, and a trigger The output scanning signal of the signal modulation unit is amplified and isolated by the high-voltage power amplifier unit to generate a scanning voltage. The high-enthalpy shock tunnel generates a shock boundary layer to induce plasma, and the scanning voltage is loaded on the probe and the probe in the model unit. , to generate current signals, the data acquisition and processing unit collects and processes the current signals and scanning voltage signals, the trigger controls the operation of the high-enthalpy shock tunnel and the delay time of scanning voltage and current signal acquisition, and generates multi-cycle complete volts within the working time of the wind tunnel. ‑Ann curve. The invention solves the problem of high time resolution for studying the electron density and electron temperature in the shock boundary layer and wake area of ​​aircraft with complex shapes by using a high-enthalpy shock wave wind tunnel.

Description

technical field [0001] The invention belongs to the research fields of hypersonic vehicle black barrier communication, target recognition, etc., and in particular relates to a hypersonic vehicle boundary layer electron density diagnosis system based on a high-frequency electrostatic probe. Background technique [0002] When the aircraft re-enters the atmosphere at hypersonic speed or cruises in the atmosphere for a long time, the flow field around the aircraft is compressed and viscous by the powerful bow-shaped shock wave in the head, and the temperature is as high as thousands or even tens of thousands of degrees. The high temperature leads to vibration excitation of air molecules , dissociation, or even ionization, thus forming a plasma sheath around the aircraft, a certain concentration of free electrons will absorb, reflect and scatter electromagnetic waves to varying degrees, ranging from interference to the transmission of electromagnetic waves, and causing communicati...

AI Technical Summary

Problems solved by technology

To obtain multiple complete volt-ampere curve cycles in a millisecond-level shock tunnel, the scanning frequency must be at least higher than 10kHz, but when the traditional single probe has such a high scanning cycle, due to the fact that the real line RLC is turned on The characteristics will cause the data to generate interference noise at the level of space potential, which will seriously affect the reliability of the experimental results

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