Calise, Giuseppe (2016) Design and Experimental Tests of an Unsteady Active Control Device for Drag Reduction of Car Shaped Bluff Bodies. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Lingua: English
Title: Design and Experimental Tests of an Unsteady Active Control Device for Drag Reduction of Car Shaped Bluff Bodies
Creators:
CreatorsEmail
Calise, Giuseppeg.calise@email.it
Date: 31 March 2016
Number of Pages: 148
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria Industriale
Scuola di dottorato: Ingegneria industriale
Dottorato: Ingegneria aerospaziale, navale e della qualità
Ciclo di dottorato: 28
Coordinatore del Corso di dottorato:
nomeemail
De Luca, Luigiluigi.deluca@unina.it
Tutor:
nomeemail
Coiro, Domenico P.UNSPECIFIED
Date: 31 March 2016
Number of Pages: 148
Uncontrolled Keywords: Bluff body; Ahmed body; Active control device; Unsteady Flow Control; Synthetic Jet; Wind tunnel tests; CFD; Electroacoustic analogy
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/03 - Meccanica del volo
Date Deposited: 11 Apr 2016 09:41
Last Modified: 31 Oct 2016 10:07
URI: http://www.fedoa.unina.it/id/eprint/10984

Abstract

Improving aerodynamic efficiency of bluff bodies is a very interesting solution for reducing fuel consumption of vehicles. Reducing drag, hopefully with no change in lift, is the best way to improve aerodynamic efficiency of such bodies: in fact, if no change in lift is experienced, the vehicle handling does not change as well. Through the years, the drag reduction was obtained mainly modifying the overall body shape with the use of passive devices, as spoilers or flaps, in order to extend laminar flow and reduce separation. Even if this approach is quite easy and fast to implement, its limits result in the poor adaptability to different car shapes or cruise conditions. Therefore, understanding how to design and control an all-purpose active device able to reduce aerodynamic drag represents a very attractive field of investigation. The work presented here deals with investigations on active control devices for drag reduction purpose: the main goal is to explore different systems and operating conditions in order to identify conditions which realize the higher drag reduction. Generally speaking, active control devices work generating a control jet near or in the separation zone, causing the flow to reattach on the body and to reduce its drag. The use of different prototypes allow to compare device effectiveness for different kind of cars: so, the effectiveness of two different active control devices has been tested on car shaped prototypes, via numerical analyses and experimental tests. In the first part of this work, a brief overview about the drag reduction problem is presented, along with the introduction of the car shaped prototypes and the active control devices under test. Secondly, numerical simulations and experimental tests are presented and discussed. Lastly, using the electroacoustic analogy, it's presented the development of a simplified model for the design of such blowing devices and for evaluating the ideal power saving achievable with an optimized device.

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