Piezoelectric fans are very low power, small, very low noise, solid-state devices that have recently emerged as viable thermal management solutions for a variety of portable electronics applications including laptop computers, cellular phones and wearable computers. Piezoelectric fans utilize piezoceramic patches bonded onto thin, low frequency flexible blades to drive the fan at its resonance frequency. The resonating, low frequency blade creates a streaming airflow directed at key electronics components. The optimization of a piezoelectric fan with two symmetrically placed piezoelectric patches is investigated through an analytical Bernoulli-Euler model as well as a finite element (FE) model of the composite piezo-beam. The closed form analytical solution is used to demonstrate that different optimal piezoceramic-to-blade length ratios and piezoceramic-to-blade thickness ratios exist for maximizing the electromechanical coupling factor (EMCF), tip deflection and rotation. Such optimization procedures provide simple design guidelines for the development of very-low power, high flow rate piezoelectric fans.

This paper presents two new design tools for lightweight aerospace structures. The first tool is the Tailored Fibre Placement (TFP) design tool TACO. It is used to optimize the fibre orientations of structures made of Carbon Fibre Reinforcement Plastics (CFRP). The optimization concept is explained and results are given for a horizontal tail plane connection beam of an aircraft. The second tool, iBuck, is a fast, semi-analytical local buckling and post-buckling tool for stiffened panels that are loaded in-plane. The panels are assumed to be representative for an aircraft fuselage and are stiffened in axial and circumferential direction. Results are presented for axially loaded panels and compared to FE-results.