Development  of  func.onal  hydrogel  pain.ng  for  fuel-‐efficient  ship

Okano  laboratory

Water resistance

870 million ton of CO2 emission in a year

Large Frictional drag

Ribret Micro-bubble

Previous research

Chitosan

Environment-Friendly And

Easy Application

Investigation of drag reduction mechanism of hydrogel coatings

Object

Drag  increase Drag  reduc.on

Hydrogel

streamwise wavy channel spanwise wavy channel

DR  =  -20.4 % DR  =  +9.3 %

Investigation of drag reduction of hydrogel by using a rotating cylinder facility

Motor Torque Meter

Acryl

Stainless

Camera

ω

Steady vortexes Turbulent