| Dr Leo Lazauskas | |
| leo@cyberiad.net |
| CURRENT PROJECTS | |
| BIOMECHANICS, HYDRODYNAMICS AND PHYSIOLOGY IN ROWING | |
| An extended research program with the Australian Institute of Sport began in Jan. 2009 and will continue into 2010. Since 2006 many existing rowing shells have been measured and digitised to provide comparisons and benchmarks for the selection of the best hulls, or the design of new hulls, to suit elite rowing crews. Validated computer models have been developed to predict the on-water performance of crews given their specific anthropometry, physiology, equipment, and rigging. Much of this work also applies to flat-water kayaking and canoeing. | |
| SHIP HYDRODYNAMICS | |
| Hull Design | The 2010 Guiness Book of World Records has recognised a new world record for the greatest distance achieved by human power on flat water (245.16km in 24 hours). The boat pedalled by Greg Kolodziejzyk was designed by Australian engineer Rick Willoughby using my hydrodynamics workbench, Michlet. After the attempt, Kolodziejzyk wrote, there is not a more efficient boat design on the planet. The existing optimisation routines in Michlet are being extended to allow fine-tuning of the human-boat system by accounting for subtle variations of hull attitude with speed, and by including a variety of human physiological and biomechanical factors. |
| Decay Rates of Ship-Waves | |
| Waves made by high-speed ships can damage beaches and structures, and they can be a hazard to other users of waterways. There are several different wave height decay models, including one I proposed in 2009. Experimental data is being gathered to validate (or reject) the models. | |
| Ship-Routing | |
| The capabilities of an existing ship motion program are being extended to allow predictions of calm-water resistance, squat, and wave patterns of thin monohulls. Computer routines are being written to allow some inter-operability with commercial ship design programs such as Delftship. | |
| 2D-Boundary Layers | |
| Several new skin-friction lines have been derived using a large number of high-fidelity, measured boundary layer velocity profiles from a variety of sources. As new experimental data is added to the database, predictions of revised skin-friction lines will need to be validated against experiments on model hulls and at full scale. | |
| Boundary Layer Separation | |
| There are many good engineering reasons to delay the onset of boundary layer separation on submarine noses and other axisymmetric bodies. Fast, accurate numerical methods allow the problem to be cast inside artifical life optimisation routines that can handle constraints and scenarios which would defeat deterministic techniques such as the method due to Mattner et al. | |
| HYDRO-KINETIC TURBINES AND WIND TURBINES | |
| The Darrieus wind turbine concept has recently been adapted for use in water. Two major drawbacks of conventional fixed pitch Darrieus turbines (whether operating in air or water) are their low starting torque, and shaking due to cyclical variations in blade angle of attack. Variable pitch can overcome both difficulties. Multi-objective memetic algorithms (MOMA) have been developed that can search for blade pitch regimes that reduce shaking, while at the same time maintaining high starting torque and high peak efficiency. | |
| The pressure exerted by high-speed ships can affect the performance of underwater turbines as well as subjecting support structures to undesirable stresses. A fast method to estimate pressures induced on the sea-bed is currently available in the program, Michlet. This method is now being extended to predict ship-induced pressures through the swept area of both horizontal axis and vertical axis turbines. | |
| LIFTING SURFACES | |
| Vortex Lattice Methods (VLM) are frequently used to estimate the lift and induced drag of thin wings, rudders, and sails. Although they can give very good, sometimes remarkable, predictions for low aspect ratio wings with straight leading edges and trailing edges, VLM can also fail cataclysmically for wings with curved edges. A canonical example is a wing with circular planform. Exact solutions are known for the flat and the parabolically-cambered cases, and these are being used to benchmark fast, robust and accurate numerical algorithms as alternatives to VLM. Modifications to the "leading-edge suction analogy" give reasonable predictions for flat wings at quite large angles of attack, typically up to 30 degrees, and often much greater. | |
| PUBLICATIONS | |
| Resistance, wave-making and wave-decay of thin ships, with particular emphasis on the effects of viscosity | |
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L. Lazauskas, PhD Thesis, Applied Mathematics, The University of Adelaide, 20 April 2009.
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| Drag on a ship and Michell's integral | |
| Ernie Tuck and Leo Lazauskas,
ICTAM 2008, Adelaide, South Australia, 24 Aug. 2008.
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| Variable pitch Darrieus water turbines | |
| B.K. Kirke and L. Lazauskas,
J. Fluid Science and Tech., Vol. 3, No. 3, June 2008, pp. 430-438. (1.78Mb pdf)
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| The wave resistance of a model ACV | |
| L. Lazauskas, Cyberiad Report, 19 Feb. 2008. (pdf)
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| Performance characteristics of a 260t displacement SES | |
| L. Lazauskas, Cyberiad Report, 19 Feb. 2008. (pdf)
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| The hydrodynamic resistance, wave wakes and bottom pressure signatures of a 5900t displacement air warfare destroyer | |
| L. Lazauskas,
Dept. Applied Mathematics Report, The University of Adelaide, 31 July 2007.
(pdf 462781 bytes).
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| Hydrodynamics of advanced high-speed sealift vessels | |
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L. Lazauskas, MSc Thesis, Applied Mathematics, The University of Adelaide, April 2005.
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| Lifting surfaces with circular planforms | |
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E.O. Tuck and L. Lazauskas, Journal of Ship Research, Vol 49, 2005, pp. 274-278.
Preprint (pdf 247,593 bytes)
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| Wave patterns and minimum wave resistance for high-speed vessels | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas.
Proceedings 24th Symposium on Naval Hydrodynamics, Fukuoka, Japan (2002).
(pdf 524692 bytes).
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| Free-surface pressure distributions with minimum wave resistance | |
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E.O. Tuck and L. Lazauskas, ANZIAM Journal, Vol. 43, 2001, (333K .pdf file).
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| Ship waves in the spirit of Michell | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas.
Paper presented at IUTAM 2000, Birmingham, July 2000. (pdf 139534 bytes).
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| The following series of reports were produced in conjunction with Scullen and Tuck P/L between 1999 and 2002. | |
| Part 6: Viscosity factors | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 118903 bytes). | |
| Part 5: Speed-up and squat | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 130351 bytes). | |
| Part 4: Extension to multihulls and finite depth | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 167172 bytes). | |
| Part 3: Near-field waves | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 210929 bytes). | |
| Part 2: Investigation of accuracy | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 417016 bytes). | |
| Part 1: Primary code and test results | |
| E.O. Tuck, L. Lazauskas and D.C. Scullen. (pdf 87506 bytes). | |
| LA class submarine portfolio - 10 knots | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas. (pdf 314254 bytes). | |
| LA class submarine portfolio - 20 knots | |
| E.O. Tuck, D.C. Scullen and L. Lazauskas.
(pdf 302614 bytes).
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| Optimum spacing of a family of multihulls | |
| E.O. Tuck and L. Lazauskas,
Schiffstechnik, Vol. 45, No. 4, Oct 1998, pp. 180-195. (pdf)
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| Wave cancellation by Weinblum-type catamarans and diamond-shaped tetrahulls, | |
| Lazauskas, L. and Tuck, E.O.,
EMAC98, 1998, pp. 299-302.
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| Low drag multihulls for sporting, commercial and military applications, | |
| Lazauskas, L. and Tuck, E.O.,
FAST97, 1997, pp. 647-652.
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| Hydrodynamic drag of some small sprint kayaks | |
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L. Lazauskas and J. Winters,
Dept. Applied Mathematics Technical Report, The University of Adelaide, Oct. 1997.
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| Hydrodynamic drag of small sea kayaks | |
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L. Lazauskas, J. Winters and E.O. Tuck,
Dept. Applied Mathematics Technical Report, The University of Adelaide, Oct. 1997.
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| Small, low drag, solar-powered, monohulls and multihulls | |
| L. Lazauskas and E.O. Tuck,
Dept. Applied Mathematics Technical Report, The University of Adelaide, Dec. 1996.
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| Unconstrained ships of minimum total drag | |
| E.O Tuck and L. Lazauskas,
Dept. Applied Mathematics Technical Report, The University of Adelaide, Dec. 1996.
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| Low drag racing kayaks | |
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L. Lazauskas and E.O. Tuck,
Dept. Applied Mathematics Technical Report, The University of Adelaide, Dec. 1996.
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| Low drag rowing shells | |
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E.O. Tuck and L. Lazauskas, 3rd Conference on Mathematics and Computers in Sport,
Bond University, Queensland, Australia, 30 Sept. - 2 Oct., 1996, pp. 17-34.
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| Experimental Verification of a Mathematical Model for Predicting the Performance of a Self-acting Variable Pitch Vertical Axis Wind Turbines | |
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B.K. Kirke and L. Lazauskas, Wind Engineering, Vol. 17, No. 2, 1993. (pdf)
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| Three Pitch Control Systems for Vertical Axis Wind Turbines Compared | |
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L. Lazauskas, Wind Engineering, Vol. 16, No. 5, 1992. (pdf)
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| Enhancing the Performance of Vertical Axis Wind Turbine Using a Simple Variable Pitch System, | |
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Kirke, B.K. and Lazauskas, L.,
Wind Engineering, Vol. 15, No. 4, 1991, pp. 187-195
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| A Novel Variable Pitch Vertical Axis Wind Turbine, | |
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Kirke, B.K. and Lazauskas, L.,
Proc. Solar '87 Conf. Australian-New Zealand Solar Energy Society, Canberra, 26-28 Nov. 1987.
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| BENCHMARKS AND BIBLIOS | |
| Airfoil bibliography | |
| VAWT bibliography | |
| Wing bibliography | |
| Some benchmark solutions for the Lifting Surface Integral Equation |