The nonlinear and multi-factor-dependent characteristics of the hydrodynamic forces acting on the aft body of a supercavitating vehicle are investigated using computational fluid dynamics (CFD). The CFD model of natural supercavitating flow is first verified and validated upon the supercavitating flow around a cavitator in the shape of a circular disk. Then the model is used to simulate the sup...

I will talk about the general energetic variational approaches for hydrodynamic systems of complex fluids. In these energetic variational approaches, the least action principle (LAP) with action functional gives the Hamiltonian parts (conservative force) of the hydrodynamic systems, and the maximum/minimum dissipation principle (MDP), i.e., Onsager’s principle, gives the dissipative parts (diss...

Keywords: Micro-swimming Micro-flows Resistive force theory Hydrodynamic interaction Bio-inspired robots Surrogate models a b s t r a c t Research on micro-swimming robots without tether is growing fast owing to their potential impact on minimally invasive medical procedures. Candidate propulsion mechanisms of robots are vastly based on microorganisms with rotating helical tails. For design of ...

Background: To clarify the mechanism of sperm penetration through the zona pellucida, the flagellar force generated by a hyperactivated spermatozoon was evaluated using the resistive force theory applied to the hyperactivated flagellar waves that were obtained from the mammalian spermatozoa. Materials and Methods: The hydrodynamic calculation of the flagellar force of the activated (non-hyperac...

We study thermal, fluctuation-induced hydrodynamic interaction forces in a classical, compressible, viscous fluid confined between two rigid, planar walls with no-slip boundary conditions. We calculate hydrodynamic fluctuations using the linearized, stochastic Navier-Stokes formalism of Landau and Lifshitz. The mean fluctuation-induced force acting on the fluid boundaries vanishes in this syste...

The generalized elastic model encompasses several physical systems such as polymers, membranes, single-file systems, fluctuating surfaces, and rough interfaces. We consider the case of an applied localized potential, namely, an external force acting only on a single (tagged) probe, leaving the rest of the system unaffected. We derive the fractional Langevin equation for the tagged probe, as wel...

The hydrodynamic behavior and propulsion mechanism of self-propelled micromotors are studied theoretically and experimentally. A hydrodynamic model to describe bubble growth and detachment is proposed to investigate the mechanism of a self-propelled conical tubular catalytic micromotor considering bubble geometric asymmetry and buoyancy force. The growth force caused by the growth of the bubble...