Our customer is a premier Defense Design and Development organization in India. They were engaged in using a planetary kneading type mixer for mixing solid rocket propellant. The customer wanted to optimize the mixing process. Optimization of mixing time and mixing speed for each mixing stage to achieve the required homogeneity was to be developed. CFD Analysis was to be carried out to optimize the addition sequence to achieve the desired homogeneity index with minimum mixing time.
Zeus Numerix as a first step developed a kinematic code which solves the instantaneous orientation of the blades at any given time. The basic algorithm used to carry out CFD analysis was to establish the flow and later solve the Scalar Transport Equations (STE) to calculate the variation of homogeneity. Laminar based CFD analysis was used to establish propellant mixing flow pattern. The STE solved for each orientation, to simulate the whole mixing cycle. The homogeneity index of the mixture was defined using the Intensity of Segregation.
Zeus Numerix developed and delivered to the client a custom software – OPTIMIXZ, for the process optimization. For the given inputs, the software predicted the mixing time to reach 85% homogeneity was 72 minutes. The software has the capability to predict mixing time for desired homogeneity and vice versa. The software can be used to find relative improvement of each mixing stages by varying each parameter one at a time.