A three-dimensional flow rate change rate sensor and measurement method based on flexoelectric effect

Abstract

A three-dimensional flow velocity change rate sensor and measurement method based on the flexoelectric effect, the sensor includes an L-shaped three-dimensional main body element and a spherical insulating material, and the L-shaped three-dimensional main body element includes an insulating layer, an electrode layer, and a flexoelectric material layer, Multi-layer stacking, the empty part is filled with insulating viscous material, the electrode layer is connected to the charge amplifier, and the output terminal of the charge amplifier is connected to the signal processing, display and storage modules; The insulating material makes each layer of the L-shaped three-dimensional main element deform, and the flexoelectric material layer produces a strain gradient in its deflection direction, generating four sets of polarized charges, which are transmitted to the charge amplifier through the electrode layer, and the three-dimensional flow velocity is displayed in real time after processing Rate of change: The sensor of the present invention is small in size, has minimal influence on the flow field, does not need to supply power to the flexoelectric material layer, has the characteristics of no external mass block, wide measuring range, good real-time performance, direct measurement, high precision, and simple structure.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a flexoelectric effect-based three-dimensional flow velocity change rate sensor and a measurement method. Background technique [0002] Most of the existing flow and velocity measurement technologies use electromagnetic measurement technology and laser measurement technology. In addition to flow velocity measurement, the real-time monitoring of flow velocity change rate also has important applications in military and daily life. For example, when the aircraft skin is in flight, the incoming flow velocity changes, the force on the skin changes, and the flight of the aircraft is affected. ; When the oil is transported through the oil pipeline, the flow rate of the oil changes, the impact force of the oil on the pipeline is different, and the damage caused to the pipeline is different; when the car is running at high speed, the change rate of the crosswind wind speed has a serious i...

AI Technical Summary

Problems solved by technology

However, the piezoelectric acceleration sensor needs to place a mass block on the piezoelectric crystal, and in order to isolate any strain of the test piece from being transmitted to the piezoelectric element, it is generally necessary to thicken the base or use a material with higher rigidity to make it. The weight of the body and the base accounts for almost half of the weight of the sensor, and the weight of the actual effective parts is small, and the piezoelectric material is a heavy metal-containing material, and its material itself is a potential threat to the environment

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