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Wave drag on asymmetric bodies.

MACSI at the department of Mathematics and Statistics at the University of Limerick invites you to a seminar

Date: Friday,  1st March 2019, Room A2-002 @ 16.00

Speaker: Dr Graham Benham, École Polytechnique, France.

Title: Wave drag on asymmetric bodies.

Abstract: More than a century ago, Michell derived an integral formula for the wave resistance on a body, using the approximation of a slender body in an irrotational, inviscid fluid (Michell 1898). The major shortcoming of this formula is that, due to the reversibility of the steady potential flow

formulation, it does not distinguish the difference in wave drag when an object with front-back asymmetry moves forwards or backwards. However, it is well known that an asymmetric body with a sharp leading edge and a rounded trailing edge produces a smaller wave disturbance moving forwards

than backwards, and this is reflected in the wave drag coefficient. In this talk, we discuss recent experimental observations investigating the effects of body asymmetry on wave drag, and show that these effects can be replicated by modifying Michell’s theory to include the growth of a symmetry-breaking

boundary layer. We demonstrate that asymmetry can have either a positive or a negative effect on drag, depending on the depth of motion and the Froude number. We discuss the implications and scope of this work in the context of sports physics, including the design of rowing, kayak and canoe boats.

 Further Information: If you have any questions regarding this seminar, please direct them to Romina Gaburro (061 2131930, email romina.gaburro@ul.ie  or Clifford Nolan (061 202766), clifford.nolan@ul.ie).

Supported by Science Foundation Ireland funding, MACSI - the Mathematics Applications Consortium for Science and Industry (www.macsi.ul.ie), centred at the University of Limerick, is dedicated to the mathematical modelling and solution of problems which arise in science, engineering and industry in Ireland.

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