Calcium phosphate growth beneath a polycationic monolayer at the air–water interface: effects of oscillating surface pressure on mineralization

Nanoscale ◽  
2010 ◽  
Vol 2 (11) ◽  
pp. 2440 ◽  
Author(s):  
Mathias Junginger ◽  
Katrin Bleek ◽  
Katarzyna Kita-Tokarczyk ◽  
Jürgen Reiche ◽  
Andriy Shkilnyy ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Surface Pressure ◽  
Water Interface ◽  
Air Water Interface ◽  
Interface Effects

scholarly journals Simulation of Air–Water Interface Effects for High-speed Planing Hull

2020 ◽  
Vol 19 (3) ◽  
pp. 398-414
Author(s):  
Naga Venkata Rakesh Nimmagadda ◽  
Lokeswara Rao Polisetty ◽  
Anantha Subramanian Vaidyanatha Iyer
Keyword(s):  
High Speed ◽  
Water Interface ◽  
Fluid Forces ◽  
Transition Speed ◽  
High Speeds ◽  
Air Water Interface ◽  
Practical Design ◽  
Actual Flow ◽  
Wetted Surface Area ◽  
Interface Effects

Abstract High-speed planing crafts have successfully evolved through developments in the last several decades. Classical approaches such as inviscid potential flow–based methods and the empirically based Savitsky method provide general understanding for practical design. However, sometimes such analyses suffer inaccuracies since the air–water interface effects, especially in the transition phase, are not fully accounted for. Hence, understanding the behaviour at the transition speed is of fundamental importance for the designer. The fluid forces in planing hulls are dominated by phenomena such as flow separation at various discontinuities viz., knuckles, chines and transom, with resultant spray generation. In such cases, the application of potential theory at high speeds introduces limitations. This paper investigates the simulation of modelling of the pre-planing behaviour with a view to capturing the air–water interface effects, with validations through experiments to compare the drag, dynamic trim and wetted surface area. The paper also brings out the merits of gridding strategies to obtain reliable results especially with regard to spray generation due to the air–water interface effects. The verification and validation studies serve to authenticate the use of the multi-gridding strategies on the basis of comparisons with simulations using model tests. It emerges from the study that overset/chimera grids give better results compared with single unstructured hexahedral grids. Two overset methods are investigated to obtain reliable estimation of the dynamic trim and drag, and their ability to capture the spray resulting from the air–water interaction. The results demonstrate very close simulation of the actual flow kinematics at steady-speed conditions in terms of spray at the air–water interface, drag at the pre-planing and full planing range and dynamic trim angles.

Sign in / Sign up

Export Citation Format

Share Document