Research, Alessandro Bottaro

Scientific interests

Waves and vortices in wall bounded shear flows
Modal and non-modal growth of instabilities
Coherent structures
Flow receptivity via adjoint methods
Optimal and robust control of transition
Active flow management with piezoelectric actuators
Compliant walls for flow management
Flapping foils/wings and beating cilia/feathers as propulsive/control devices
Biomimetics ... see in particular the cartoon below of the ultimate biomimetic airplane ... appeared in 2012 as the cover of a special issue (Vol. 340) of Comptes Rendus Mécanique on "Biomimetic Flow Control" ,
Frank Fish

Media coverage

Il ruolo delle piume, by Michele Catanzaro, Le Scienze, April 2009, n. 488, pp. 36-37

Fake feathers could take the drag out of flights, by Colin Barras, New Scientist, online edition, April 13, 2009

Condensed versions of the article above have appeared on April 13, 2009, on the Science Section of ISEGORIA, on the Technology Section of OK4me2, on the site of the United Nations University (UNU-MERIT), and on the Rotary Wing Forum

Coating plane wings in feathers could reduce drag, by Tudor Vieru, SOFTPEDIA™, April 13, 2009

Boeing and Airbus to learn efficient flight from birds?, Russia Today, SciTech Section, April 13, 2009

Aviões com penas prometem menos turbulência, Intel, Tech Update, Futurama, April 13, 2009

There have been a number of other interesting reports on brasilian blogs/news agencies/etc. such as on Abril.com (by Guilherme Pavarin, April 13, 2009), on Brasil Portais (April 14), on Rock'n Tech Podcast (April 14), and on Digital Touch (April 14)

Kunstmatige veren kunnen vliegtuig efficënter maken", by Dennis Rijnvis, NU, April 14, 2009. The same article appeared - on the same day - on E-lijn and on Nederlandse Luchtvaart. On April 22 it was also posted on the Wetenschap & Technologie Forum of NeoWeb

'Feathered' aircraft may fly faster, NETPark, April 14, 2009

Vliegtuig met veren?", by Elmar Veerman, Noorderlicht, April 14, 2009

On April 14, 2009, an article entitled Fake feathers could increase efficiency of airplanes was published on the Irish Sun, on HighBeam Research, and on Daily India. Similar versions of the same article came out the same day on the Science News of Silver Scorpio, on the Thaindian News, on Webindia123.com, on Asia Top News World, on the World News Section of New Kerala on the Science Sections of Buzz7, on Yahoo! India News, on Khabar Express, on One India, and on many other blogs/posts/bulletin boards across India

Feathered coatings could help planes fly, by Katie Scott, Wired Magazine, News Science, April 14, 2009. The same article was translated and appeared on the Italian edition of Wired

Artificial bristles that mimic feathers could make airplanes more efficient, Cafe Terra, Science Section, April 15, 2009

Künstliche Federn können Flugzeug effizienter machen, by Dennis Rijnvis, D News, Wissenschaft, April 15, 2009

Fake feathers can up airplane efficiency appeared on the Sci-Tech Section of both ZeeNews and Technology.am on April 15, 2009

'Feathers' can up plane efficiency, The Times of India, Health & Science, online edition, April 16, 2009. Here is the version which was printed on The Times of India

Vogelfedern sollen Flugzeuge effizienter machen, by Wolfgang Weitlaner, came out on the Hightech Section of Pressetext, on Innovations Report and on Tierschutz News, April 16, 2009. The Pressetext article above has been used to update the voice feder (feather) on the German version on Wikipedia

Vederen kunnen prestaties vliegtuigen verbeteren was posted on Nieuws on April 16, 2009. The next day it appeared on Zita and on the Express. It was also published on April 20, 2009, on IETS met ECONOMIE

Vederipak kan prestaties vliegtuigen verbeteren, Managing21, Skynet Blogs, Technology Section, April 17, 2009

Fjäderskrud gör flygplan effektivare, by Håkan Abrahamson, Ny Teknik, online edition, April 21, 2009. A shorter article, entitled Fågelfjädrar ska minska motståndet, came out in print on the April 29, 2009, edition of Ny Teknik, no. 18, p. 21

Feather coating to reduce drag, CREAX MoreInspiration Newsletter, June 2009 (first appeared on May 20, 2009, on the More Inspiration site)

Airplane Wings Go to the Birds?, by Gail Helgason, The Pegg, online edition, July 2009. Here is the printed version of the article (The PEGG, June 2009, p. 21)

Winging It, by Roberta Kwok, Conservation Magazine, online edition, July 2009. The article has also come out in the July-September 2009 printed edition of Conservation Magazine, Vol. 10, No. 3, p. 38

Fly like a bird, by Isabelle Kliger, Aero Magazine, the bi-yearly magazine of Volvo Aero, No. 2, 2009, p. 40.

There have also been reports in many other languages, such as Finnish, Cech (see also here), Russian, Chinese, Polish, etc.

"Sulla scia di Icaro", by A. Bottaro, J. Favier, J. Guerrero, D. Venkataraman and H. Wedin , Sapere, October 2009, No. 5, pp. 66-77.

... and finally there is this nice cartoon by a popular Indian cartoonist ...

Ajit Ninan

Så lite behövs för att starta turbulens, by Mats Lewan, Ny Teknik, March 22, 2011

Man vs. wild, by Jim Gourley, Lava Magazine, June/July 2011, pp. 108-114.

The future of flight: Changes in the air, The Economist, Technology Quarterly, September 3, 2011, pp. 12-14. The online version of the article is here.

A selection of publications (1996-present)

Goulpié P., Klingmann B.G.B. & Bottaro A., "Goertler vortices in boundary layers with streamwise pressure gradient: Linear theory", Phys. Fluids, Vol. 8, 1996, pp. 451-459

Bottaro A. & Klingmann B.G.B., "On the linear breakdown of Goertler vortices", Eur. J. Mech. B/Fluids, Vol. 15, no. 3, 1996, pp. 301-330

Bottaro A., Klingmann B.G.B. & Zebib A. "Goertler vortices with system rotation", Theoret. Comput. Fluid Dyn., Vol. 8, 1996, pp.325-347

Randriarifara T. & Bottaro A., "Effect of spanwise system rotation on spatially developing Dean vortices", Int. J. Num. Methods Fluids, Vol. 23, 1996, pp.1275-1286

Bottaro A. & Zebib A., "Goertler vortices promoted by wall roughness", Fluid Dynamics Research, Vol. 19, 1997, pp.343-362

Carrière P., Bottaro A. & Metzener P., "Wavelength selection in Rayleigh-Bénard convection between horizontal boundaries of finite conductivity", Eur. J. Mech. B/Fluids, Vol. 16, 1997, 483-508

Luchini P. & Bottaro A., "Goertler vortices : A backward-in-time approach to the receptivity problem", J. Fluid Mech., Vol. 363, 1998, 1-23

Bottaro A. & Luchini P., "Goertler vortices : Are they amenable to local eigenvalue analysis ", Eur. J. Mech. B/Fluids, Vol. 18, 1999, 47-65

Corbett P. & Bottaro A., "Optimal perturbations for boundary layers subject to stream-wise pressure gradient", Phys. Fluids, Vol. 12, 2000, pp.120-130

Luchini P. & Bottaro A., "Linear stability and receptivity analyses of the Stokes layer produced by an impulsively started plate", Phys. Fluids, Vol. 13, 2001, pp. 1668-1678

Andersson P., Brandt L., Bottaro A. & Henningson D.S., "On the breakdown of boundary layer streaks", J. Fluid Mech, Vol. 428, 2001, pp. 29-60

Corbett P. & Bottaro A., "Optimal linear growth in swept boundary layers", J. Fluid Mech, Vol. 435, 2001, pp. 1-23

Walther S., Airiau C. & Bottaro A., "Optimal control of Tollmien-Schlichting waves in a developing boundary layer", Phys. Fluids, Vol. 13, 2001, pp. 2087-2096

Corbett P. & Bottaro A., "Optimal control of non-modal disturbances in boundary layers", Theoret. Comput. Fluid Dyn., Vol. 15 (2), 2001, pp. 65-81

Airiau C., Walther S. & Bottaro A., "Boundary layer sensitivity and receptivity", C. R. Mécanique, Vol. 330, 2002, pp. 259-265

Bottaro A., Corbett P. & Luchini P.,"The effect of base flow variation on flow stability", J. Fluid Mech., Vol. 476, 2003, pp. 293-302

Airiau C. & Bottaro A., Walther S. & Legendre D., "A methodology for optimal laminar flow control: Application to the damping of Tollmien-Schlichting waves in a boundary layer", Phys. Fluids, Vol. 15, 2003, pp. 1131-1145

Galletti, B. & Bottaro, A., "Large scale secondary structures in duct flow", J. Fluid Mech., Vol. 512, 2004, pp. 85-94

Zuccher S., Luchini P. & Bottaro A., "Algebraic growth in a Blasius boundary layer: Optimal and robust control by mean-flow suction in the nonlinear regime", J. Fluid Mech., Vol. 513, 2004, pp. 135-160

Biau D. & Bottaro, A., "Optimal perturbations and minimal defects: Initial paths of transition to turbulence in plane shear flows", Phys. Fluids, Vol. 16, 2004, pp. 3515-3529

Gavarini I., Bottaro A. & Nieuwstadt F.T.M., "The initial stage of transition in cylindrical pipe flow: Role of optimal base-flow distortions", J. Fluid Mech., Vol. 517, 2004, pp. 131-165 (see also the paper by the same authors entitled "Coherent states in transitional pipe flow", in Laminar-Turbulent Transition and Finite Amplitude Solutions, T. Mullin and R. Kerswell (Eds.), Springer, 2005, pp. 163-172)

Biau, D. & Bottaro, A., "The effect of stable thermal stratification on shear flow stability", Phys. Fluids, Vol. 16, 2004, pp. 4742-4745

Gavarini I., Bottaro A. & Nieuwstadt F.T.M., "Optimal and robust control of streaks in pipe flow", J. Fluid Mech., Vol. 537, 2005, pp. 187-219

Zuccher S., Bottaro A. & Luchini P., "Algebraic growth in a Blasius boundary layer: Nonlinear optimal disturbances", Eur. J. Mech. B/Fluids, Vol. 25, 2006, pp. 1-17

Grea B.-J., Luchini P. & Bottaro A., "Ray theory of flow instability and the formation of caustics in boundary layers", IMFT Internal Report, 2005

Bottaro A., Soueid H. & Galletti B., "Formation of secondary vortices in turbulent square-duct flow", AIAA Journal, Vol. 44, no. 4, 2006, pp. 803-811 (a preliminary version of this paper was presented as invited paper AIAA 2005-5309 at the 4th AIAA Theoretical Fluid Mechanics Meeting, 6-9 June 2005, Toronto, Ontario, Canada)

Galletti B., Bottaro A., Bruneau C.-H. & Iollo A., "Accurate model reduction of transient and forced wakes", Eur. J. Mech. B/Fluids, Vol. 26, no. 3, 2007, pp. 354-366

Guaus A. & Bottaro A., "Effect of wall compliance on curved channel flow instabilities", Proc. Royal Soc. A, Vol. 463, 2007, pp. 2201-2222

Nouar C., Bottaro A. & Brancher J.P., "Delaying transition to turbulence in channel flow: revisiting the stability of shear thinning fluids", J. Fluid Mech., Vol. 592, 2007, pp. 177-194

Biau D., Soueid H. & Bottaro A., "Transition to turbulence in duct flow", J. Fluid Mech., Vol. 596, 2008, pp.133-142

Wedin H., Biau D., Bottaro A. & Nagata M., "Coherent flow states in a square duct", Phys. Fluids, Vol. 20, 2008, 094105

Dauptain A., Favier J. & Bottaro A., "Hydrodynamics of ciliary propulsion", J. Fluids and Structures, Vol. 24, 2008, pp. 1156-1165

Soueid H., Guglielmini L., Airiau C. & Bottaro A., "Optimization of the motion of a flapping airfoil using sensitivity functions", Computers and Fluids, Vol. 38, 2009, pp. 861-874

Biau D. & Bottaro A., "An optimal path to transition in a duct", Phil. Transact. Royal Soc., Vol. 367, 2009, pp. 529-544

Favier J., Dauptain A., Basso D. & Bottaro A., "Passive separation control using a self-adaptive hairy coating", J. Fluid Mech., Vol. 627, 2009, pp. 451-483

Guaus A., Airiau C., Bottaro A. & Kourta A., "Effect of wall compliance on the linear stability of Taylor-Couette flow", J. Fluid Mech., Vol. 630, 2009, pp. 331-365

Wedin H., Bottaro A. & Nagata M., "Three-dimensional traveling waves in a square duct", Phys. Rev. E, Vol. 79, 2009, 065305(R)

Nouar C. & Bottaro A., "Stability of the flow of a Bingham fluid in a channel: eigenvalue sensitivity, minimal defects and scaling laws of transition", J. Fluid Mech., Vol. 642, 2010, pp. 349-372

Hoepffner J., Bottaro A. & Favier J., "Mechanisms of non-modal energy amplification in channel flow between compliant walls", J. Fluid Mech., Vol. 642, 2010, pp. 489-507

Bottaro A., "A 'receptive' boundary layer", J. Fluid Mech., Vol. 646, 2010, pp. 1-4

Cherubini S., Robinet J.-C., Bottaro A. & De Palma P., "Optimal wave packets in a boundary layer and initial phases of a turbulent spot", J. Fluid Mech., Vol. 656, 2010, pp. 231-259

Okino S., Nagata M., Wedin H. & Bottaro A., "A new nonlinear vortex state in square duct flow", J. Fluid Mech., Vol. 657, 2010, pp. 413-429

Cherubini S., De Palma P., Robinet J.-Ch. & Bottaro A., "Rapid path to transition via nonlinear localized optimal perturbations in a boundary-layer flow", Phys. Rev. E, Vol. 82, 2010, 066302

Campa G., Camporeale S.M., Guaus A., Favier J., Bargiacchi M., Bottaro A., Cosatto E. & Mori G., "A quantitative comparison between a low order model and a 3D FEM code for the study of thermoacoustic combustion instabilities", ASME paper GT2011-45969, Proceedings of the ASME Turbo Expo 2011, June 6-10, 2011, Vancouver, Canada

Monokrousos A., Bottaro A., Brandt L., Di Vita A. & Henningson D.S. , "Non-equilibrium thermodynamics and the optimal path to turbulence in shear flows", Phys. Rev. Letters, Vol. 106, 2011, 134502

Cherubini S., De Palma P., Robinet J.-Ch. & Bottaro A. , "Edge states in a boundary layer", Phys. Fluids, Vol. 23, 2011, 051705

Cherubini S., De Palma P., Robinet J.-Ch. & Bottaro A. , "The minimal seed of turbulent transition in the boundary layer", J. Fluid Mech., Vol. 689, 2011, pp. 221-253

Guerrero J.E., Maestro D. & Bottaro A. , "Biomimetic spiroid winglets for lift and drag control", C. R. Mécanique, Vol. 340, 2012, pp. 67-80

Bottaro A. & Ansaldi T. , "An asymptotic formulation for the infusion of a therapeutic agent into a solid tumor modelled as a poroelastic medium", x, under review 2011

Venkataraman, D. & Bottaro A. , "Flow separation control on a symmetric aerofoil via a porous, compliant coating", x, under review 2011

Cherubini S., De Palma P., Robinet J.-Ch. & Bottaro A. , "A purely non-linear route to transition approaching the edge of chaos in a boundary layer", x, under review 2011

Slides of recent lectures

"Routes to transition in shear flows", Invited lecture at the SIAM-AMS, Hydrodynamic Instability and Flow Control Conference, Salt Lake City, Utah, July 2003

"Optimal and robust control of streaks in wall bounded shear flows", Keynote lecture at FLOWCOMAG, International Symposium on Flow Control by Tailored Magnetic Fields, Dresden, Germany, April 2004

"Minimal defects", Invited lecture at the IUTAM Symposium, Non-uniqueness of Solutions to the Navier-Stokes Equations and their Connection to the Laminar-Turbulent Transition, Bristol, U.K., 9-11 August 2004

"Secondary vortices in turbulent square-duct flow", Invited lecture at the 4th AIAA Theoretical Fluid Mechanics Conference, Toronto, Ontario, Canada, 6-9 June 2005

"Large amplitude coherent states in boundary layer" , Invited lecture at the International Symposium on Fluid Motion and Chaos, Kyoto, Japan, 22-23 February 2006

"Interaction between vortices and compliant walls", Invited seminar at DIMEC, University of Salerno, 11 May 2007

"Optimal disturbances: a sexy and useless concept?", Invited seminar at the Meeting of the GDR "Turbulence" and "Dycoec", IRPHE, Marseille, France, 22 May 2007

"Hydrodynamics of beating cilia", Invited keynote lecture at the IUTAM Symposium on Unsteady Separated Flows and Their Control, Corfu, Greece, 22 June 2007 (the conference paper is here)

"A linear model of transition to turbulence", Invited seminar at the Meeting of the GDR "Turbulence" and "Controle", Ile d'Oléron, France, 13 May 2008

The video and the slides of the invited presentation 'Optimal paths to transition in a duct' delivered at the Isaac Newton Institute for Mathematical Sciences, Cambridge, UK, 9 September 2008, in the frame of the programme on "The Nature of High Reynolds Number Turbulence" are available here.

"A new technique for the control of the wake - and the reduction of pressure drag - behind a bluff body", Invited seminar at the Meeting of the Royal Institution of Naval Architects and ATENA Meeting on Applications of CFD to Naval Design, Genova, Italy, 27 November 2008

"Hairfoils: Passive actuators for flow control", Invited presentation at the Fluid and Elasticity 2009 conference, Carry-le-Rouet, France, 23-26 June 2009

"The optimal and near-optimal wavepacket in a boundary layer and its ensuing turbulent spot", Invited seminar at LadHyX, Ecole Polytechnique, Paris, France, 3 December 2009 (see also .avi movie of a turbulent spot). The same seminar was delivered also at KTH, Mechanics, Stockholm, Sweden, on February 11, 2010.

"Effect of a poroelastic layer on lift and drag over an airfoil", Plenary talk at the International Forum on Flow Control, Poitiers, France, 8-10 December 2010

"Localized, nonlinear optimals", Invited seminar at the 9th ERCOFTAC SIG33 Workshop, Progress in Transition Modeling and Control, Toledo, Spain, 28-30 September 2011

Interested in a research project (Laurea, M.S., Ph.D. or postdoc) on one of the topics above? Send an email to alessandro.bottaro@unige.it

OLD: The Marie Curie Programme FLUBIO

VERY OLD: The Marie Curie Programme WAVES in Toulouse

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