Hydrodynamic and Acoustic Modelling Capability Statement
The prediction, measurement and improvement of hydrodynamic performance for maritime platforms and operations requires a multi-disciplinary approach, incorporating ship design, hydrodynamics, marine acoustics, applied oceanography, instrumentation, and data processing skills. These skills are held by two collaborating research entities at Curtin University – the Fluid Dynamics Research Group and the Centre for Marine Science and Technology.
The Fluid Dynamics Research Group (FDRG) comprises a multi-skilled body of engineers and scientists committed to research and development. The Group serves to advance and disseminate understanding of the fundamental fluid dynamics that underpins novel applications-driven research. Scientific interests lie in the study of vortex dynamics, wave propagation, hydrodynamic stability, shear-layer phenomena, mixing, free-surface flows, multiphase physics and reacting flows using theoretical, computational and experimental methods.
The Centre for Marine Science and Technology (CMST) is a designated University research centre with a wide range of expertise including a unique combination of underwater acoustics, underwater technology and hydrodynamics, covering numerical modelling, scale experiments and full scale sea trials.
Three modes of operation are available:
- Commercial-in-confidence consulting, research and development
- Accessing state and federal government grant schemes
- Postgraduate student research. The student may be supplied by the client.
The preferred process is dependent upon the requirements of the client.
A wide range of clients have utilised our services including: DSTO, Austal Ships, Marine Department Hong Kong, JFA, NZ Maritime Safety Authority, Voyage Management Systems, Woodside, Dept of Defence, Maunsell and Tenix Defence.
FDRG and CMST have linkages to a number of research providers, giving access to exceptional expertise and facilities. Curtin operates under a Strategic Alliance with DSTO and has recently applied for membership of the RPDE defence program. The Australian Maritime College has been a long-term partner and holds a Memorandum of Understanding with Curtin. Curtin staff have utilised its hydrodynamic testing facilities extensively during projects.
Complex, multi-phase and bubbly flow modelling
We have capability and experience in experimental, theoretical and numerical techniques that are required for the modelling of complex flows. The technical aspects of detailed modelling of complex flows such as bubbly flows, slurries, multi-phase and self-convective flows require a multi-faceted approach beyond numerical modelling alone. The direct numerical modelling of these complex systems is generally at the limit of modern numerical modelling capabilities, and approaching this problem from a purely numerical standpoint can be both costly and time-consuming. Good experimental data combined with fundamental theoretical as well as numerical modelling provide a more efficient means of understanding these systems and result in a greater depth of analysis than could be obtained from numerical modelling alone.
Steady state flow around marine vehicles
We conduct extensive fundamental research into predicting the steady flow of water around ships. This research includes wave wake prediction, hydrodynamic pressure, resistance, dynamic sinkage and trim, in both deep and shallow water.
These methods have been used to perform underkeel clearance calculations for ships in shallow water, based on dynamic sinkage, trim and heel. The underkeel clearance calculations may be in the form of squat tables, developing guidelines for ship entry into a harbour, optimizing channel design or assessing grounding risk. CMST has worked with New Zealand Maritime Safety Authority, Marine Dept. Hong Kong and several industry partners on commercial-in-confidence projects developing underkeel clearance guidelines for port operations.
We have carried out research into the flow around underwater vehicle control surfaces using Fluent CFD software on a suite of high performance computers, and have contributed to a joint venture on the feasibility of establishing a virtual hydrodynamics facility at the Australian Marine Complex, WA.
Unsteady flow around surface vessels
We have developed a sea loads and motions program that calculates the coupled heave and pitch motions and the added resistance due to the waves. It also includes the calculation of shear force and longitudinal bending moment.
A version of this program ‘SeaKeeper’ has been licensed to Formation Design Systems as part of their MaxSurf suite of programs, and is used by more than 100 naval architects worldwide.
Extensive validation of the program has been conducted through comparison with towing tank test results and full scale sea trials of various hull forms.
Curtin has also done extensive research into ship motions in shallow water, as part of its underkeel clearance consulting for ports exposed to ocean swells.
Motion control systems
Curtin has designed, built and tested the electronics and software for the motion stabiliser system for high speed ferries. A vital part of this work involved the modelling and simulation of vessel performance with and without control systems activated.
The system has been fitted successfully to 22 vessels ranging in length from 37m to 86m that are in operation on routes all around the world from Europe to Asia and from the Caribbean to the Pacific. Motion reductions are usually in the range of 35 – 50% when the vessel is operating at cruising speed.
CMST researchers have established a spin-off company Sea Gyro Pty Ltd, to design and manufacture vessel roll stabiliser systems that perform efficiently and economically whether the vessel is at anchor or under way. Sea Gyros have been installed in power yachts, dive boats and fishing vessels in five countries.
ROV Hydrodynamics and Control
A scale model of a Work-Class ROV has been subjected to a program of tank testing as part of a research program into the complex hydrodynamics of underwater vehicle motion. The results from the testing have been incorporated into numerical simulations of vehicle behaviour that have formed the basis for automated ROV station-keeping systems and real-time visualisation of the response of ROVs to current and control inputs.
Cavitation modelling
CMST is able to calculate cavitation effects on propellers and fixed foils, either theoretically/empirically, or using the experimental facilities at the Australian Maritime College. CMST has previously provided consulting services on assessing cavitation damage on propellers.
Umbilical Hydrodynamic Behaviour
The hydrodynamics of thin umbilicals is poorly understood, particularly at low angles of attack. CMST has carried out modelling to investigate the behaviour of umbilicals and towed hydrophone arrays in response to towed vessel motion and ambient current. This work can be used to predict individual hydrophone position within an array, as well as the effects on an ROV of the current-induced drag on the umbilical.
Towed array processing
CMST has an ongoing project with DSTO to develop techniques that will allow warships and submarines to use towed hydrophone arrays to measure their own acoustic signatures, and thereby determine their vulnerability to both passive and active sonar.
Map of underwater noise radiated by a tug
Environmental noise
Scientific connections with the Hydroacoustic Monitoring section of the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) allow CMST to gain access to the CTBT hydroacoustic data from the Cape Leeuwin listening station for initiating new environmental studies. In particular, these data are being used to create an electronic atlas of environmental noise of different origins (e.g. biological, seismic, other natural, and man-made) in seas around the southwest coast of Western Australia.
Personnel
Kim Klaka PhD, MAppSc, CPEng, MIEAust, MRINA, MSNAME
Centre Director with 35 years experience in naval architecture, specialising in ship motions prediction and measurement.
Tim Gourlay PhD, BSc[Hons], GRINA, GSNAME
Research Fellow in ship hydrodynamics with particular expertise in the flow around ships.
Andrew King, BEng
Wide experience in modelling various free-surface, dual-phase, non-newtonian, self-convective thermal flows
Mark Pitman BEng
Research Fellow specialising in fluid-structure interaction, stability of hydroelastic systems and modeling optimization.
Tony Lucey PhD
Engineering Dean with 25 years experience in industrial fluid dynamics modelling and experiments.
Alec Duncan PhD, MAppSc, BAppSc, MIEEE
Senior Research Fellow with a wealth of experience in acoustic modelling, signal processing, electronic design and development, software for real-time systems, data acquisition and data analysis.
Amos Maggi BAppSc(Hons)
Research Fellow with a background in physics and measurement science. Experienced in acoustic modelling and the development of software for data acquisition and analysis.
For further details on our services please contact:
Dr. Kim Klaka
Director
CMST
Curtin University of Technology
GPO Box U1987
Perth
Western Australia 6845
Tel: 08 9266 7380
Fax: 08 9266 4799
Email: k.klaka
