Computational Marine Ethology Research Institute

Turbulent jets are ubiquitous in many engineering applications ranging from ink-jet printing to cooling mitigation strategies for gas-turbine combustion fins. Moreover, jet applications related to propulsion and energy production applications are commonplace.

 

In nature, examples of turbulent jets are also widely found with notable examples of wind blowing through orographic gaps (canyons) and in the complex mixing seen in estuaries. Jet physics include a core collapse followed by an expansion of the shear layer that can be described by the jet spreading half-angle (in practice, ranging from 7-20 degrees). Jet self-similarity is known to be strongly a function of Reynolds number as lower Reynold number flows reach a self-similar regime sooner than high Reynolds flows. As an example, Figure 1 represents a recent turbulent jet study in which a passive scale is introduced into a quiescent domain [1].

 

For marine life, the intriguing inking behavior of coleoid cephalopods (squid and octopus) is noteworthy, see Figure 2. These animals, when agitated, produce a jet of ink that serves as a masking agent allowing the cephalopods to covertly retreat. Despite the significant range in cephalopods size and shape, the universal ability to engineer a cloud of ink with seemingly optimal dispersal characteristics is noted. Although propulsion has been studied using computational techniques, ink spread has not.

 

Therefore, linking behavior with the physics of jet dispersal is of interest.

 

COMERI’s research plan is to:

• Construct a computational jet flow simulation matrix of various cephalopods inking strategies with emphasis on determination of ethology to maximize jet dispersion.

• What is the characteristic Reynolds number for various cephalopods? What is the time-history of the ink pulse relative to the animals motion?

• Are there any jet-in-cross flow mitigation strategies/behavior that can be elucidated that may produce a more effective jet dispersal?

• Publish and disseminate the results of any funded research study.