同心二重円筒流路の押し込み流れにおいて内円筒に作用する抗力を利用した第一法線応力差の測定

－第1報：定常状態における押し込み反力に基づく算出方法－

抄録

A measurement technique for the first normal stress difference using a conventional rheometer with a concentric cylinder flow cell is examined. The conventional rheometer, which can control the up and down speeds of an inner cylinder of the concentric cylinder flow cell and can also measure the thrust force, is used in this technique. The other additional instruments or the optional devices are not required. The inner cylinder is pushed down with a constant velocity into the sample filled in the cup. The resistant force acting on the inner cylinder is measured during this motion. The resistant force is caused by the buoyancy, the shear stress acting on the side surface of the inner cylinder and the pressure acting on the top and bottom of the inner cylinder. The buoyancy and the shear stress can be calculated based on the shape of the inner cylinder and the moving velocity. If the inlet and outlet pressure drop can be ignored, the pressure caused by the first normal stress difference can be evaluated from the thrust force and the shear viscosity.