Permeability of the 3D braided preform based onthe unidirectional flow measurement

The saturated and unsaturated permeabilities of the 3D braided preform were measured by unidirectionalflow. The capillary pressure was determined through the permeabilities experiment s. The influences of the fibervolume f raction on the saturated and unsaturated permeabilities were studied. The effect s of braiding parameter andinjection pressures on permeability were analyzed. A plot of different injection pressures against the square distanceof the flow f ront was fitted with a st raight line for a certain period of time. The capillary pressure was determined asthe horizontal axis intercept value. The experimental result s show that saturated and unsaturated permeabilitiesdecrease with increasing the fiber volume f ractions. The saturated permeability is larger than the unsaturated permeability. The braiding st ructure influences the permeability. The unsaturated permeability decreases with increasing the braiding angle. The accurate permeability does not depend on the injection pressure and it denotes a decreasing behavior until it reaches a stabilized value.