Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Propagation of waves generated by a pressure disturbance moving in a channelPublication . Rodrigues, S. R. A.; Soares, C. Guedes; Santos, João AlfredoThis paper studies the effect of ship speed and water depth on the propagation of ship generated waves. The ship is represented by a moving pressure distribution function at the free surface that is able to reproduce most of the phenomena involved in wave propagation. Results are obtained for a ship sailing along a coastal stretch made of a sloping bottom and a constant depth region. The results show that in the sloping bottom the crests of waves are bent along the slope and in the constant depth the standard Kelvin wave patterns can be found for the subcritical regime. In the critical regime the wave system is characterized by significant diverging waves and for a supercritical regime, the transverse waves disappear. © 2015 Taylor & Francis Group, London.
- On pressure disturbance waves in channels: Solitons, jets and ripplesPublication . Moreira, Roger Matsumoto; Chacaltana, J. T. A.; Santos, João Alfredo; Rodrigues, S. R. A.; Neves, C. F.; Nascimento, M. F.Pressure disturbance waves are computed via a fully nonlinear, unsteady, boundary integral formulation for various Froude and Bond numbers. Three moving pressure distributions are introduced in the numerical model to evaluate the produced near and far-field wave patterns in a channel. For Froude numbers equal to one, classical runaway solitons are obtained on the fore of the moving pressure patch whereas "stern" waves are radiated away. "Step-like" pressure distributions give different responses to the free-surface flow, with upward breaker jets and steeper "stern" waves. For supercritical and subcritical flows, steady solitons and stationary trenches moving at the same speed of the pressure distribution are obtained, respectively. Surface tension affects directly the free-surface flow: runaway solitons are suppressed; instead, a "building-up plateau" and a capillary wave train are formed ahead and on the rear of the moving pressure patch for long computational run-times. For supercritical flows, small-scale ripples and parasitic capillaries appear on the fore of the steady soliton; oppositely, for low Froude numbers, stationary trenches become shallower compared to the corresponding pure-gravity wave solutions. Nonlinear results show that near and far-field wave patterns are significantly affected by moving pressure distributions and surface tension.