Fumiya Fujisawa’s scientific contributions

What is this page?

This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (1)

FIG. 1: Configuration for a penguin trying to defecate towards his/her rear side. A penguin stands on the rock with the height h from the ground. We parameterize the ejection angle θ with the initial velocity v = (v0x, v0y) We estimate a flying distance d of the faeces from the origin O.
FIG. 4: The maximum flying distance dmax as a function of h. The inset shows the corresponding angle θmax.
FIG. 5: Calculated penguin's rectal pressures Pt with and without the coefficient of the contraction C, as functions of the viscosity η. The dash-dotted curve represents the result of Ref. [2]. For comparison, we also show P0.
Projectile Trajectory of Penguin's Faeces and Rectal Pressure Revisited
  • Preprint
  • File available

July 2020

·

10,708 Reads

·

Fumiya Fujisawa

We discuss a trajectory of penguins' faeces after the powerful shooting due to their strong rectal pressure. Practically, it is important to see how far faeceses reach when penguins expel them from higher places. Such information is useful for keepers to avoid the direct hitting of faeceses. We estimate the upper bound for the maximum flight distance by solving the Newton's equation of motion. Our results indicate that the safety zone should be 1.34 meters away from a penguin trying to poop in typical environments. In the presence of the viscous resistance, the grounding time and the flying distance of faeces can be expressed in terms of Lambert {\it W} function. Furthermore, we address the penguin's rectal pressure within the hydrodynamical approximation combining Bernoulli's theorem and Hagen-Poiseuille equation for viscosity corrections. We found that the calculated rectal pressure is larger than the estimation in the previous work.

Download