In the frame of the Cleansky 2 projects SYNJET3C and FLOCOS, CEDRAT TECHNOLOGIES (CTEC) and TRISITEC are collaborating with both FRAUNHOFER and ONERA institutes, two major European research leaders in the development of Synthetic Jet Actuators (SJA) for Aerospace applications. While SYNJET3C project is dedicated to SJA mechanical designs and optimisation, as well as testing including wind tunnel tests, FLOCOS project is dedicated to the design and manufacturing of a specific SJA drive Electronic called SADS (Synthetic Jet Actuator Drive System).
The piloting of APA's composite shell by SA75D power amplifier offers new opportunities for dynamic new applications. Two in particular were received and are being studied: the design of a compact table tensile micro machine for characterizing stress-strain laws at high strain rate of wires, fibers, strands and textile samples that will usefully complete the fleet of dynamic testing machines available, the generation of synthetic jets of air pulsed also studied at ONERA. The energy capacity (displacement, force) without or with an external linear load were modeled versus the rise time using the Simulink code and experimentally measured using a very light device. Other identified improvements remain to be implemented both at the APA's actuators as the Amplifier SA75D to get some gains.
The objective of the European Cleansky project is to develop new technologies for future aircraft enabling a 20-30% fuel burn reduction and related CO2 emissions and a similar reduction in noise levels compared to current aircraft. One of the ways to reach this goal is to improve the aerodynamic performances of current high lift devices. Active flow control is unanimously seen as the best mean to reach this objective. By suppressing flow separation and/or delaying stall, active flow control will increase wing aerodynamic performances. The partnership between CTEC and ONERA in the framework of the VIPER project has led to the design, manufacturing and test of an innovative pulsed jet actuator based on a CTEC amplified piezo-actuator (APA). Its aim is to provide a pulsed sonic jet up to 500Hz with a mass flow around 34 g/s through a slot 1mm wide and 80mm long. Coupled with CTEC SA75D switching power amplifier this actuator produces the expected sonic jet with an electrical consumption around 40W thanks to energy recovery. The results of the actuator characterisation (mechanical, fluidic) are presented in this paper.
This paper presents research and development results of the high performances piezoelectric actuators. Performed studies were concentrated on the improvement of three major parameters: stroke, maximum driving frequency and operational temperature. Two, new actuators were presented and described in this paper. First presented actuator has increased maximum displacement. This actuator has doubled the stroke of standard, long stroke actuators. Improvement of the second actuator was concentrated on increase of constant driving frequency. Finally, special encapsulations designed for both actuators allow using them at high temperatures. Development of these two, new actuators was done simultaneously to the improvement of the electronics. High power amplifier presented in this paper provides sufficient current to drive both actuators at high frequencies.
Nowadays, piezoelectric actuators (PA) are used in fast power actuations and high power applications as requested in machine tools or helicopters flap applications. Regarding to the low power capability and high loss ratios of linear amplifiers, Switching Power Amplifiers (SA75X) is designed by Cedrat Technologies to drive piezoelectric actuators in such applications. The switching technique (up to 100 kHz) allows high current peaks required by impulse or by high frequency applications on large piezoelectric actuators (or actuators in parallel) and allows energy harvesting.
LA75B : A powerful electronic that makes APA sing higher in volume and larger in frequency.
In previous editions of Flux Magazine, we have presented some of the range of piezo actuators developed by CEDRAT RECHERCHE. These actuators cover a whole range of displacements from a few centimetres to sub-micrometric distances and from low to ultrasonic frequencies.The fields of application are expanding rapidly and use the latest developments in electronics for their power supply and control.