The Canadian Society for Bioengineering The Canadian society for engineering in agricultural, food, environmental, and biological systems. La Société Canadienne de Génie Agroalimentaire et de Bioingénierie La société canadienne de génie agroalimentaire, de la bioingénierie et de l’environnement Paper No. 06-122 Network Analysis of Grain Bulk Pore Structure Using High Resolution X-ray Computed Tomography Images S. Neethirajan Graduate Student, The Canadian Wheat Board Centre for Grain Storage Research, Biosystems Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada D. S. Jayas Distinguished Professor, Canada Research Chair in Stored-Grain Ecosystems, Associate Vice-President (Research), University of Manitoba, Winnipeg, MB, R3T 2N2, Canada Written for presentation at the 2006 CSBE – SCGAB Annual General Meeting Sponsored by CSBE Edmonton, Alberta July 16-19, 2006 Abstract. The knowledge of distribution of pore space inside grain bulks is essential for determining the effect of porosity on the airflow resistance of grains. In this study, the geometry of pore structure and the 3D-distribution of void spaces inside the grain bulks were studied using high resolution X-ray computed tomography (CT) images. The quantitative analysis of the architecture, geometry and spatial continuity of the pore network inside grain bulks was done using image processing algorithms. Image analysis methods were applied to the binary 3D X-ray CT images on the spatial distribution of voids to generate the connected, individualized pore objects of different size and shapes. Morphometric parameters such as 3D air path volume distribution, air path thickness, Euler number, fragmentation index, structure model index were calculated three dimensionally based on hexahedral marching cubes volume model and marching cubes 3D surface construction algorithm. The results showed that the connectivity of airspace and the non uniform distribution of void space inside grain bulks were responsible for the difference in resistance to airflow of grain bulks between horizontal and vertical directions. Keywords. pore network, airflow resistance, grain bulks, 3D image analysis, X-ray CT, connectivity. Papers presented before CSBE/SCGAB meetings are considered the property of the Society. In general, the Society reserves the right of first publication of such papers, in complete form; however, CSBE/SCGAB has no objections to publication, in condensed form, with credit to the Society and the author, in other publications prior to use in Society publications. Permission to publish a paper in full may be requested from the CSBE/SCGAB Secretary, PO Box 23101, RPO McGillivray, Winnipeg MB R3T 5S3 or contact bioeng@shaw.ca. The Society is not responsible for statements or opinions advanced in papers or discussions at its meetings.