Permeability and porosity estimation in resin transfer molding process

This paper presents methods for determining the permeability and the porosity of the fiber preform in resin transfer molding for one dimensional flow case. A direct method is presented first which takes advantage of the invertibility of the governing equations for parameter estimation. An adaptive estimation method is studied later. The parameters are estimated by using the time history of the pressure and the flow rate at the injection gate and the flow front location. The direct method is compared with the adaptive estimation method. The results show that the parameters can be determined accurately by the direct method when there is small measurement noise. Adaptive estimation algorithms can estimate the parameters in the presence of large measurement noise. Effect of various parameters on the estimation such as the weighting factor, the cut-off frequency of the low pass filter, and the forgetting factor is studied in the paper.