Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-05-17T06:41:48.841Z Has data issue: false hasContentIssue false

Pressure and work analysis of unsteady, deformable, axisymmetric, jet producing cavity bodies

Published online by Cambridge University Press:  25 March 2015

Michael Krieg
Affiliation:
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA Institute for Networked Autonomous Systems, University of Florida, Gainesville, FL 32611, USA
Kamran Mohseni*
Affiliation:
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA Institute for Networked Autonomous Systems, University of Florida, Gainesville, FL 32611, USA
*
University of Florida, PO Box 116250, Gainesville, FL 32611, USA. Email address for correspondence: mohseni@ufl.edu

Abstract

This work lays out a methodology for calculating the pressure distribution internal to a generic, deformable, axisymmetric body with an internal cavity region whose deformation expels/ingests finite jets of water. This work is partially motivated by a desire to model instantaneous jetting forces and total work required for jellyfish and cephalopod locomotion, both of which can be calculated from the internal pressure distribution. But the derivation is non-specific and can be applied to any axisymmetric, deformable body (organic or synthetic) driving fluid in or out of an internal cavity. The pressure distribution over the inner surface is derived by integrating the momentum equation along a strategic path, equating local surface pressure to known quantities such as stagnation pressure, and correlating unknown terms to the total circulation of characteristic regions. The integration path is laid out to take advantage of symmetry conditions, inherent irrotationality, and prescribed boundary conditions. The usefulness/novelty of this approach lies in the fact that circulation is an invariant of motion for inviscid flows, allowing it to be modelled by a series of vorticity flux and source terms. In this study we also categorize the various sources of circulation in the general cavity–jet system, providing modelling for each of these terms with respect to known cavity deformation parameters. Through this approach we are able to isolate the effect of different deformation behaviours on each of these circulation components, and hence on the internal pressure distribution. A highly adaptable, transparent, prototype jet actuator was designed and tested to measure the circulation in the cavity and the surrounding fluid as well as the dynamic forces acting on the device during operation. The circulation in both the jet and cavity regions shows good agreement with the inviscid modelling, except at the end of the refill phase where circulation is lost to viscous dissipation. The total instantaneous forces produced during actuation are accurately modelled by the pressure analysis during both expulsion and refilling phases of the jetting cycle for multiple deformation programs. Independent of the end goal, such as propulsion, mixing, feeding etc., the efficiency of the process will always be inversely proportional to the total energy required to drive the system. Therefore, given a consistent output, efficiency is maximized by the minimum required energy. Here it is observed (somewhat counter-intuitively) that, for both jetting and refilling, total work required to drive the fluid is lower for impulsive velocity programs with fast accelerations at the start and end of motion than sinusoidal velocity programs with smoother gradual accelerations. The underlying cause is that sinusoidal programs result in a peak in pressure (force) simultaneously with maximum deflection velocity of the deformable boundary driving fluid motion; for the impulsive programs these peaks are out of phase and overall energy consumption is reduced.

Type
Papers
Copyright
© 2015 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amitay, M., Smith, B. L. & Glezer, A.1998 Aerodynamic flow control using synthetic jet technology. In 36th Aerospace Sciences Meeting and Exhibit. AIAA Paper. 98-0208.CrossRefGoogle Scholar
Anderson, E. J. & DeMont, E. 2000 The mechanics of locomotion in the squid Loligo pealei: locomotory function and unsteady hydrodynamics of the jet and intramantle pressure. J. Expl Biol. 203, 28512863.Google Scholar
Anderson, E. J. & Grosenbaugh, M. A. 2005 Jet flow in steadily swimming adult squid. J. Expl Biol. 208, 11251146.CrossRefGoogle ScholarPubMed
Bartol, I. K., Krueger, P. S., Stewart, W. J. & Thompson, J. T. 2009 Hydrodynamics of pulsed jetting in juvenile and adult brief squid Lolliguncula brevis: evidence of multiple jet ‘modes’ and their implications for propulsive efficiency. J. Expl Biol. 212, 11891903.Google ScholarPubMed
Bartol, I. K., Krueger, P. S., Thompson, J. T. & Stewart, W. J. 2008 Swimming dynamics and propulsive efficiency of squids throughout ontogeny. Integr. Compar. Biol. 48 (6), 114.CrossRefGoogle ScholarPubMed
Didden, N. 1979 On the formation of vortex rings: rolling-up and production of circulation. Z. Angew. Mech. Phys. 30, 101116.Google Scholar
Gallas, Q., Holman, R., Nishida, T., Carroll, B., Sheplak, M. & Cattafesta, L. 2003 Lumped element modeling of piezoelectric-driven synthetic jet actuators. AIAA J. 41 (2), 240247.CrossRefGoogle Scholar
Gilly, W. F., Markaida, U., Baxter, C. H., Block, B. A., Boustany, A., Zeidberg, L., Reisenbichler, K., Robison, B., Bazzino, G. & Salinas, C. 2006 Vertical and horizontal migrations by the jumbo squid Dosidicus gigas revealed by electronic tagging. Mar. Ecol. Prog. Ser. 324, 117.Google Scholar
Glezer, A. & Amitay, M. 2002 Synthetic jets. Annu. Rev. Fluid Mech. 34, 503529.Google Scholar
Helmholtz, H. 1867 On integrals of hydrodynamical equations which express vortex-motion. Phil. Mag. 4, 485512.CrossRefGoogle Scholar
Holman, R., Utturkar, Y., Mittal, R., Smith, B. L. & Cattafesta, L. 2005 Formation criterion for synthetic jets. AIAA J. 43 (10), 21102116.Google Scholar
Johnson, W., Soden, P. D. & Trueman, E. R. 1972 A study in jet propulsion: an analysis of the motion of the squid, Loligo volgaris . J. Expl Biol. 56, 155165.Google Scholar
Kaden, H. 1931 Aufwicklung einer unstabilen Unstetigkeitsfläche. Ing.-Arch. 79, 93112.Google Scholar
Kirby, B. J. 2010 Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices. Cambridge University Press.Google Scholar
Krieg, M., Klein, P., Hodgkinson, R. & Mohseni, K. 2011 A hybrid class underwater vehicle: bioinspired propulsion, embedded system, and acoustic communication and localization system. Mar. Technol. Soc. J. Spec. Ed. Biomimetics Mar. Technol. 45 (4), 153164.Google Scholar
Krieg, M. & Mohseni, K. 2008 Thrust characterization of pulsatile vortex ring generators for locomotion of underwater robots. IEEE J. Ocean. Engng 33 (2), 123132.Google Scholar
Krieg, M. & Mohseni, K. 2013 Modelling circulation, impulse and kinetic energy of starting jets with non-zero radial velocity. J. Fluid Mech. 719, 488526.Google Scholar
Krueger, P. S. 2005 An over-pressure correction to the slug model for vortex ring circulation. J. Fluid Mech. 545, 427443.Google Scholar
Krueger, P., Dabiri, J. & Gharib, M. 2006 The formation number of vortex rings formed in a uniform background co-flow. J. Fluid Mech. 556 (1), 147166.Google Scholar
Lamb, H. 1945 Hydrodynamics. Dover.Google Scholar
McCormick, D. C.2000 Boundary layer separation control with directed synthetic jets. In 38th Aerospace Sciences Meeting, AIAA paper 2000-0519.Google Scholar
Merhaut, J. 1981 Theory of Electroacoustics, pp. 209274. McGraw-Hill.Google Scholar
Mohseni, K. 2004 Impulse extremization in synthetic jet actuators for underwater locomotion and maneuvering. In Proceedings of the 23rd International Conference on Offshore Mechanics and Arctic Engineering, Vancouver, Canada.Google Scholar
Mohseni, K. 2006 Pulsatile vortex generators for low-speed maneuvering of small underwater vehicles. Ocean Engng 33 (16), 22092223.Google Scholar
Mohseni, K. & Mittal, R. 2014 Synthetic Jets: Fundamentals and Applications. CRC Press.Google Scholar
Moslemi, A. A. & Krueger, P. S.2009 Effect of duty cycle and stroke ratio on propulsive efficiency of a pulsed jet underwater vehicle. In 39th AIAA Fluid Dynamics Conference, San Antonio, TX.Google Scholar
Moslemi, A. A. & Krueger, P. S. 2010 Propulsive efficiency of a biomorphic pulsed-jet vehicle. Bioinspir. Biomim. 5, 036003.Google Scholar
Moslemi, A. A. & Krueger, P. S. 2011 The effect of Reynolds number on the propulsive efficiency of a biomorphic pulsed jet underwater vehicle. Bioinspir. Biomim. 6, 026001.Google Scholar
O’Dor, R. K. 1988 The forces acting on swimming squid. J. Expl Biol. 137, 421442.Google Scholar
O’Dor, R. K. & Webber, D. M. 1986 The constraints on cephalopods: why squid aren’t fish. Can. J. Zool. 64, 15911605.Google Scholar
Olesen, J. 1972 The hydraulic mechanism of labial extension and jet propulsion in dragonfly nymphs. J. Compar. Physiol. 81 (1), 5355.CrossRefGoogle Scholar
Pullin, D. I. 1978 The large-scale structure of unsteady self-similar rolled-up vortex sheets. J. Fluid Mech. 88 (3), 401430.Google Scholar
Pullin, D. I. & Phillips, W. R. C. 1981 On a generalization of Kaden’s problem. J. Fluid Mech. 104, 4553.Google Scholar
Rosenfeld, M., Katija, K. & Dabiri, J. O. 2009 Circulation generation and vortex ring formation by conic nozzles. Trans. ASME J. Fluids Engng 131, 091204.Google Scholar
Rosenhead, L. 1963 Laminar Boundary Layers. Oxford University Press.Google Scholar
Saffman, P. G. 1992 Vortex Dynamics. Cambridge University Press.Google Scholar
Sawant, S., Oyarzun, M., Sheplak, M., Cattafesta, L. & Arnold, D. 2012 Modeling of electrodynamic zero-net mass-flux actuators. AIAA J. 50 (6), 13471359.Google Scholar
Smith, B. L. & Glezer, A. 2002 Jet vectoring using synthetic jets. J. Fluid Mech. 458, 134.Google Scholar
Trueman, E. R. 1968 Motor performance of some cephalopods. J. Expl Biol. 49, 495505.Google Scholar
Utturkar, Y., Mittal, R., Rampunggoon, P. & Cattafesta, L.2002 Sensitivity of synthetic jets to the design of the jet cavity. In 40th AIAA Aerospace Sciences Meeting, Reno, NV. AIAA Paper 2002-0124.Google Scholar
Walker, J. D. A., Smith, C. R., Cerra, A. W. & Doligalski, T. L. 1987 The impact of a vortex ring on a wall. J. Fluid Mech. 181, 99140.Google Scholar
Weymouth, G. D. & Triantafyllou, M. S. 2012 Global vorticity shedding for a shrinking cylinder. J. Fluid Mech. 702, 470487.Google Scholar
Weymouth, G. D. & Triantafyllou, M. S. 2013 Ultrafast escape of a deformable jet-propelled body. J. Fluid Mech. 721, 367385.Google Scholar