125 二次元対向流れにおける流動複屈折測定を用いた定常平面伸張粘度測定(S34-1 複雑流体の流れとその応用(1),S34 複雑流体の流れとその応用)  [in Japanese] 125 Measurement of steady planar elongational viscosity in two-dimensional opposing flow by using flow-birefringence method  [in Japanese]

In the purpose of development of new elongational rheometer to estimate planar elongational viscosity for various fluids, we investigated the way to generate planar elongational flow by using two-dimensional opposing flow. The relationship between elongation rate at the stagnation point and flow rate was measured from results of flow visualization. And elongational stress was evaluated from flow birefringence at the stagnation point by application of the stress-optic rule. From both results, planar elongational viscosity was estimated. The planar elongational viscosity compared with the results measured by using 4-roll mill flow cell and squeeze flow cell and they showed good agreement.