Samuel Smith

 

Date commenced:

22/02/16

Full name:         

Samuel Michael Halleen Smith

Study/Department Area:

Naval Architecture/Hydrodynamics

Profile Type:

PhD Candidate

Qualifications:

Bachelor of Engineering (Naval Architecture) (Honours) at Australian Maritime College

History

 

During my studies in Naval Architecture at the Australian Maritime College (AMC) I was exposed to the Hydrocontest. The Hydrocontest is an international student competition dedicated to efficiency in the maritime industry with particular focus on hydrofoils. Becoming fascinated with the engineering behind using underwater wings to lift boats out of the water, I dedicated a lot of my time towards designing, constructing and analysing hydrofoils.

Wanting to work on state-of-the-art hydrofoil design, I have set my sights on being a part of the America’s Cup. With the international sailing competition bringing flying boats into the spotlight, the teams are at the forefront of the engineering behind hydrofoils.

With the ability to undertake my PhD candidature at one of the world’s leading research facilities at the AMC Cavitation Research Laboratory, I can expand on my work and hopefully place myself on the forefront of hydrofoil technology.

 

Research Project/s summary/description

The performance of control surfaces on submarines are significantly affected by the turbulent flow, hull boundary layer and embedded wakes generated by the forebody. Consequently, the control surfaces are subject to unsteady loading and hence be a source of vibration and noise production. For these effects to be minimised, insight into the flow physics and excitation spectra are required.

The problem of unsteady airfoil loading has received considerable attention since the initial work by Theodorsen (1935) and von Karman and Sears (1938), for an oscillating flat plate, and Sears (1941) for a thin airfoil encountering a sinusoidal gust. Much of this work is motivated by aeronautical applications involving prediction of radiated noise as well as unsteady loading. Detailed reviews are provided in recent work by Howe (2001 and 2002), Mish and Devenport (2006a and 2006b) and Glegg and Devenport (2009 and 2010). These recent studies refer to a significant body of work in which enhancements to the Sears linearised inviscid theory have been made. In some cases use has been made of modern computational capabilities to numerically solve various inviscid formulations. Despite the extensive development of theoretical models there are relatively few complimentary experimental studies (e.g. McKeough and Graham, 1980 and Jackson et al., 1973). Mish and Devenport note this as a motivation for their extensive wind tunnel experiments additional to numerical studies. These experimental investigations have typically involved two or three-dimensional airfoils immersed in grid generated turbulence with lift spectra measured directly or derived from surface pressure measurements.

 

For the present problem, the structured turbulence of wall bounded flows is of particular interest. Modern experimental and numerical research has significantly increased the understanding of these flows (e.g. Smits et al., 2011). Current computational capabilities, specifically Large Eddy Simulation (LES), have now developed sufficiently where modelling of flows representative of the present problem may reasonably be achieved (e.g. Fureby, 2007, Alin et al., 2010a and 2010b). In particular, insight can be gained into realistic turbulent structures affecting and interacting with an immersed hydrofoil whether modelled as a flat plate turbulent boundary layer or submarine afterbody.

 

As a complement to numerical investigation of this problem it is proposed that experiments be performed of suitable hydrofoil models immersed to varying extents within a flat plate turbulent boundary. Measurements and data gathered would be suitable for comparison with LES prediction and provide a basis for more detailed analysis and design of control surfaces. The following proposal details the rationale behind the experimental setup, techniques and equipment development, models and tasking to carry out the experiments.

 

PhD Thesis Title

Unsteady loading of hydrofoils immersed in a turbulent boundary layer.

Research Supervisors:

Assoc. Prof. Paul Brandner, Dr. Bryce Pearce, Dr. David Clarke, Dr. Yungpeng Xue

Associated Researchers:

Assoc. Prof. Paul Brandner, Assoc. Prof. Jonathan Binns, Dr. Bryce Pearce

Research Interests:

Unsteady Loading of Hydrofoils

Hydrofoil-Free Surface Interaction

LES Development

Supercavitating Hydrofoils

Ride Control of Hydrofoil Equipped Vessels

Teaching Interests / Subjects:

Computational Fluid Dynamics

Hydrodynamics

Professional Awards:

Civilian Defence Engineering Scholarship in Naval Architecture