Flow–structure interaction of a starting jet through a flexible circular nozzle

In the present study, flow–structure interaction of a starting jet through flexible nozzle is experimentally investigated, with focus on optimal flexibility for thrust generation. Water slug impulsively accelerated cylindrical nozzle, fabricated silicone rubber varying flexibility. general, modifies vortical structure and augments jet. The measurement surface deformation revealed that back-and-forth wave propagation responsible jet-vortex evolution augmenting Combining hydrodynamic conservation equations linearized shell theory, we also formulated governing equations, dominated by two relevant dimensionless parameters: effective acceleration time ( $\varPi _0$ ) stiffness _1$ ). Asymptotic analysis equation showed speed $\hat {c}$ expressed as {c}=(\varPi _{0}^{2}\varPi _{1}/2)^{0.5}$ , momentum maximized at {c}=\hat {c}_{crit}$ $\simeq 3.0$ ), condition which release elastic energy stored during contraction to synchronized instant termination acceleration. While achievable maximum velocity decreases attributed reduced flow inside nozzle.