Electrohydrodynamic air amplifier for low-energy airflow generation - experimental proof-of-concept

Abstract

Electrohydrodynamic (EHD) air amplification is a novel way to generate airflow with low energy consumption. This study experimentally evaluates how air amplification via the Coanda effect raises the overall flow rate performance of EHD airflow generation. Due to the complex multiphysical nature of EHD air amplification, the design stages are investigated one by one starting with a simple emitter-collector configuration. First, regular EHD flow was studied in a 150×150×500 mm³ channel. Then, a dielectric material was added to determine its influence on the electric field. The impact of a converging nozzle on the EHD-generated airflow was subsequently studied. Lastly, the converged nozzle airflow was used as a supply air stream on a plate to facilitate air amplification of the surrounding air. We show the proof of concept for an EHD air amplification system. After a voltage threshold of 14 kV, amplified airstreams up to an amplification factor of 3 were measured. Maximum airflow rates of about 15 m³ h^-1 were obtained shortly before electric breakdown at 22 kV. Compared to regular EHD, we achieved a higher flow rate for the same electric energy invested. As a measure of efficiency, the flow rate per electric power increased up to 66 % in EHD air amplification with normal EHD as the benchmark. The proposed EHD air amplifier operates at atmospheric pressures and lays the groundwork for further optimization studies to position EHD air amplification as an alternative to conventional fans or standard EHD airflow generation.