Coanda Synthetic Jet Deflection Apparatus and Control

Abstract

This paper presents the theoretic and numerical background of a recent patent about an innovative Coanda Effect application. This innovative jet is designed to enhance the controllability of the system and to encompass static deflection of the fluid jet but especially the dynamic variation of the Coanda deflection with a very low inertia. This innovative nozzle is formerly named H.O.M.E.R., acronym of “High-speed Orienting Momentum with Enhanced Reversibility”. H.O.M.E.R. constitutes an application based on a dual propeller system. It explains how a vector controllable flux can be produced, with the ability to change angular position dynamically as a function of momentum (or velocity) of the two primitive streams. CFD based simulation in a configuration is provided and main calculations are produced to define the control model. Nozzle design guidelines are provided. The proposed system can be used both for aeronautical naval propulsion and industrial applications

Integrated flight/thrust vectoring control for jet-powered unmanned aerial vehicles with ACHEON propulsion

“…Also, The ACHEON propulsion has involved a dedicated close-loop controller inside which is so-called PEACE controller to guarantee its fast response and stability. The details about the PEACE control can be seen in the research work [10][11][12]. More importantly, no matter what the response time is, the stability of high attack angle maneuvers here is actually guaranteed by two key mechanisms: The first one is the time-scale separation principle, which means that the stability is feasible when the response time of outer slow-loop controller is 4 more times than the one of the inner fast-loop controllers.…”

“…2 and Fig. 3, the dynamic response time is very short and about 0.2s because of the merits of no-moving elements for fluidic thrust-vectoring [11][12]and therefore the feedback error is relatively small compared with the response time of the fastest loop (about 2s). Also, The ACHEON propulsion has involved a dedicated close-loop controller inside which is so-called PEACE controller to guarantee its fast response and stability.…”

“…And based on the transient CFD simulation result in [12], a boundary restrict conditions for the three TV parameters can be defined as:…”

“…It aims to verify a novel propulsion system with thrust vectoring capabilities formally named HOMER (High-speed Orienting Momentum with Enhanced Reversibility) and recently patented by the University of Modena and Reggio Emilia in Italy, together with a smart and effective active control system based on PEACE (Plasma Enhanced Actuator for Coanda Effect) a study by the Universidad de Beira Interior in Portugal [10][11][12]. The successful integration of these two new concepts involves solving the way in which high speed streams mix and their interaction with Coanda surfaces such that a vectoring system can be realized which will have a wide spectrum of applications, a precursor to a long-term step advancement in aerial (and naval propulsion and industrial) systems by providing a directionally controllable fluid jet [13].…”

Design methods of Coanda effect nozzle with two streams

“…After the initial bibliographic analysis by Trancossi [7,8] and Pascoa [9], it has been produced a combined CFD and theoretical activity. A preliminary model of the Coanda adhesion of a fluid as a function of angular velocity of a two ducted fan units [10] has realized. Turbulence has been…”