Research Activities

Overview

Here is a poster summarizing my lab's focus and a few videos related to the lab's work:

• An overview of the CP3
• Biomass Feeding - Nathan Gasteyer (an additional description - not a video.)
• CP3 Characterization Lab - Dr. Dhananjay Pai
• Twin Screw Wet Granulation - Shankali Pradhan
• Liquid contact spreading in granular flows - Liza Easo
• Purdue's Continuous Tablet Manufacturing Pilot Plant - Mariana Moreno, Sudarshan Ganesh, and Yasasvi Bommireddy

My laboratory is part of Purdue's Center for Particulate Processes and Products (CP3).

In order to learn more about my research interests, I've provided a list of my graduate student thesis titles and abstracts, as well as a list of journal publications with links to abstracts. Lastly, I've summarized some of the research topics in which I'm currently involved along with my collaborators.

Theses Advised and Links to Abstracts

Student	Degree and Year	Title (click for abstract)	Pretty Pictures
Elizabeth Foesch Thompson	M.S., Purdue University, 2024, co-advised with Prof. Marcial Gonzalez (ME)	Use of triaxial testing to obtain the shear failure surface in the modified Drucker-Prager Cap model
Zhengpu Chen	Ph.D., Purdue University, 2022, co-advised with Prof. Kingsly Ambrose (ABE)	Development and validation of a DEM-based model for predicting grain damage
Abhishek Paul	Ph.D., Purdue University, 2022, co-advised with Prof. Marcial Gonzalez	A continuum model for milled corn stover in a compression feed screw
Prathamesh Sankhe	M.S., Purdue University, 2021	DEM Parameter Calibration Methodology for Cohesive Powders Using a Ring Shear Tester
Nathan Gasteyer	M.S., Purdue University, 2020, co-advised with Prof. Marcial Gonzalez	Modeling biomass transport in a compression screw feeder
Kunal Pardikar	Ph.D., Purdue University, 2020	Finite Element Method (FEM) Modeling of Hopper Flow
Zhengpu Chen (ABE Outstanding MS Student Award Winner)	M.S. in Agricultural and Biological Engineering, Purdue University, 2019, co-advised with Prof. Kingsly Ambrose	Developing a Validated Model for Predicting Grain Damage using DEM
Yu Liu	Ph.D., Purdue University, 2019, co-advised with Prof. Marcial Gonzalez	Modeling Granular Material Mixing and Segregation Using a Finite Element Method and Advection-Diffusion-Segregation Equation Multi-scale Model
Rohit Kumar	Ph.D., Purdue University, 2018	Predicting Breakage of Needle-shaped Large Aspect Ratio Particles Using the Discrete Element Method (DEM)
Shankali Pradhan	Ph.D. in Chemical Engineering, Purdue University, 2017, co-advised with Prof. Jim Litster	Quality by Design in Twin Screw Granulation
Harsh Ranjan	M.S., Purdue University, 2017	A Methodology for DEM Parameter Calibration
Liza Easo	Ph.D., Purdue University, 2017	Liquid Dispersion In Sheared Particulate Material
Siddhartha Agarwal	M.S., Purdue University, 2017	Modeling the Scaling of Intra-Tablet Coating Variability
Shrikant Swaminathan	Ph.D., Purdue University, 2016	Modeling Picking on Pharmaceutical Tablets
Yu Liu	M.S., Purdue University, 2016	Modifications to Johanson's Roll Compaction Model for Improved Relative Density Predictions
Nitin Khola	M.S., Purdue University, 2015	Correlations for Shear-Induced Percolation in Granular Shear Flows
Xia Hua	Ph.D., Purdue University, 2014	Modeling the Dynamics and Stresses of Elongated Particles in Vertical Axis Mixers
Tim Patterson	M.S., Purdue University, 2014	Prediction of the Stress at the Inlet of the Nip Region in a Roll Compactor
Rahul Kumar	Ph.D., Purdue University, 2014	Modeling Coating Variability in a Continuous Tablet Coating Pan
Steven Dale	Ph.D. in Industrial and Physical Pharmacy, Purdue University, 2014, co-advised with Prof. Jim Litster	Internal Structures of Wet Granulation Agglomerates: Measurement, Formation, and Influence on Granule Breakage
Kristine Alston	M.S., Purdue University, 2012	Mechanical Property Variability in Lactose Monohydrate
Avik Sarkar	Ph.D., Purdue University, 2011	Modeling a Continuous Granular Mixer Using Periodic Discrete Element Method Sub-models
Tuhin Sinha	Ph.D., Purdue University, 2011	Investigation of Compaction, Young's Modulus, and Tensile Strength of Binary Powder Mixtures Using the Multi-Particle Finite Element Method (MPFEM)
Madhusudhan Kodam	Ph.D., Purdue University, 2010	Attrition of Pharmaceutical Tablets
Ben Freireich	Ph.D., Purdue University, 2010	A Compartmental Approach to Studying Particle Motion in Mixer/Coaters Using Discrete Element Modeling
Arjun Kalbag	Ph.D., Purdue University, 2009	Modeling Inter- and Intra-tablet Coating Variability of Pan Coated Tablets
Vincent Hoon	M.S. in Computer Science, Purdue University, 2007, co-advised with Prof. Ananth Grama	Visualization of Discrete Element Method Simulations (The ParticleVis code.)
Alexis Dechelette	M.S., Purdue University, 2007, co-advised with Prof. Paul Sojka	Shear-thinning Drops Impacting Flat Surfaces
Rahul Bharadwaj	Ph.D., Purdue University, 2006	Dilute Granular Flow around Immersed Obstacles
William Ketterhagen	Ph.D. in Chemical Engineering, Purdue University, 2006, co-advised with Prof. Jennifer Curtis	Modeling Granular Segregation during Hopper Discharge
Jose Cordova	M.S., Purdue University, 2005	Dilute Granular Flow around an Immersed Cylinder and Oblique Granular Shock Waves
Bradley Pederson	M.S., Purdue University, 2005, co-advised with Prof. Farshid Sadeghi	The Influence of Cage Flexibility on Bearing Dynamics and Performance
Matthew Duncan	M.S., Purdue University, 2004, co-advised with Prof. Chuck Krousgrill	An Investigation into the Damping Performance of Single and Multiple Particle Impact Dampers
Nicholas Prenger	M.S., Purdue University, 2003, co-advised with Prof. Farshid Sadeghi	Modeling the Dynamics of Rolling Element Bearings using ADAMS
Niranjan Ghaisas	M.S., Purdue University, 2003, co-advised with Prof. Farshid Sadeghi	Dynamics of Cylindrical and Tapered Rolling Element Bearings using the Discrete Element Method
Atul Aphale	M.S., Purdue University, 2003	Segregation of Granular Fertizliers from a Spinner Spreader
Junyoung Park	Ph.D., Purdue University, 2003	Modeling the Dynamics of Fabric in Rotating Horizontal Drums
Nathan Bolander	M.S., Purdue University, 2002, co-advised with Prof. Farshid Sadeghi	An Experimental Investigation of Thrust Washer Lubrication
Sanga Reddy Peerreddy	M.S., Purdue University, 2002	Modeling Particle-laden Viscous Flows using an Eulerian-Lagrangian Approach
Nagendra Shishodia	M.S., Purdue University, 2001	Segregation due to Particle-induced Buoyant Forces in Granular Systems
Vishal Saheta	M.S., Purdue University, 2001, co-advised with Prof. Farshid Sadeghi	Dynamics of Rolling Element Bearings using the Discrete Element Method
Dimuth Fernando	M.S., Purdue University, 2001	Size Segregation in Granular Beds Subject to Continuous and Discrete Oscillations
Shun Gao	M.S., Clemson University, 1998	Granular Flow through a Live Wall Hopper

Publications with Links to Abstracts

• Zhou, Z., Gasteyer, N., Chen, Z., Ambrose, R.P.K., and Wassgren, C., 2025, "The design and use of an optical punch for maize kernel internal crack detection", Biosystems, Vol. 257, Article 104242. https://doi.org/10.1016/j.biosystemseng.2025.104242.
• Issa, S.F., Issa, M.S., Nauman, E., Wassgren, C., Schwab, C., Ahsan, Z.S., Nour, M., and Field, W., 2024, "Tensile force limits of the sheep spine: Comparison to forces required to extricate grain entrapped victims", Journal of Agromedicine, Vol. 30, No. 1, pp. 49-56. doi: 10.1080/1059924X.2024.2426491.
• Koleilat, L., Paasche, C.K., Wade, J., Hanson, J., Wassgren, C., and Mort, P., 2024, "Fluid bed granulation - Process optimization", Powder Technology, Vol. 449, Article 120358. doi: 10.1016/j.powtec.2024.120358.
• Nagaraju, V., Jange, C., Wassgren, C., Ambrose, R.P.K., 2024, "Understanding urea polymorphism and co-crystallization to develop enhanced fertilizers: A review", Journal of Environmental Chemical Engineering, Vol. 12, No. 6, Article 114308. doi: 10.1016/j.jece.2024.114308.
• Zhao, Y., Russell, A., Ambrose, K., and Wassgren, C.R., 2024, "Prediction of air purifier effectiveness for eliminated exhaled droplets in a confined room", Processes, Vol. 12, No. 9, 1917. doi: 10.3390/pr12091917.
• Henry, K.L., Wassgren, C., and Mort, P., 2024, "Continuous chute-flow rheometer: A multi-modal approach to dense granular flows", Particuology, accepted 2024 Aug 23. doi: 10.1016/j.partic.2024.08.011.
• Koleilat, L., Paasche, C.K., Wade, J., Hanson, J., Wassgren, C., and Mort, P., 2024, "Flow field analysis of a toroidal flow fluidized bed granulator", Chemical Engineering Research and Design, Vol. 208, pp. 359-368. doi: 10.1016/j.cherd.2024.07.003.
• Jange, C.G., Graef, R., Penn, C., Wassgren, C.R., and Ambrose, K., 2023, "Controlling nutrient leaching profile of urea granules through structural modification", Journal of the ASABE, Vol. 66, No. 6, pp. 1415-1424. doi: 10.13031/ja.15675.
• Paul, A., Meyer, M., Zhang, J., Chen, K., Gunyon, M., Matar, M., Meiners, J., Selking, E., Tu, Y-J., Wasem, R., Gonzalez, M., and Wassgren, C., 2023, "A laboratory-scale compression feed screw for characterizing continuous feeding of dense granular materials", Bioresource Technology Reports, Article 101554. doi: 10.1016/j.biteb.2023.101554.
• Chen, Z., Wassgren, C., Tamrakar, A., and Ambrose, R.P.K., 2023, "Validation of a DEM model for predicting grain damage in an industrial-scale handling system", Smart Agricultural Technology, Article 100274. doi: 10.1016/j.atech.2023.100274.
• Chen, Z., Wassgren, C., and Ambrose, R.P.K., 2023, "Development and validation of a DEM model for predicting compression damage of maize kernels", Biosystems Engineering, Vol. 230, pp. 480-496. doi: 10.1016/j.biosystemseng.2023.05.004.
• Jange, C.G., Wassgren, C.R., and Ambrose, K., 2023, "Investigating the role of dry compaction and layer-wise agglomeration to control the dissolution of granular urea fertilizer", Powder Technology, Vol. 420, Article 118382.
• Jange, C.G., Wassgren, C.R., and Ambrose, K., 2023, "The significance of tablet internal structure on disintegration and dissolution of immediate release formulas: A review", Powders, Vol. 2, No. 1, pp. 99-123.
• Chen, Z., Wassgren, C., and Ambrose, R.P.K., 2022, "Development and validation of a DEM model for predicting impact damage of maize kernels", Biosystems Engineering, Vol. 22, pp. 16 - 33, doi: 10.1016/j.biosystemseng.2022.09.012.
• Almeida, L.C., Bharadwaj, R., Eliahu, A., Wassgren, C.R., Nagapudi, K., and Muliadi, A.R., 2022, "Capsule-based dry powder inhaler evaluation using CFD-DEM simulations and Next Generation Impactor data", European Journal of Pharmaceutical Sciences, Vol. 175, Article 106226, doi: 10.1016/j.ejps.2022.106226.
• Ketterhagen, W.R. and Wassgren, C.R., 2022, "A perspective on calibration and application of DEM models for simulation of industrial bulk powder processes", Powder Technology, Vol. 402, Article 117301, doi: 10.1016/j.powtec.2022.117301.
• Jange, C.G., Wassgren, C.R, and Ambrose, R.P. Kingsly, 2021, "Disintegration and release kinetics of dry compacted urea composites: A formulation and process design study", EFB Bioeconomy Journal, Vol. 1, No. 100020, doi: 10.1016/j.bioeco.2021.100020.
• Guo, Y., Liu, Q., Li, Y., Li, Z., Jin, H., Wassgren, C., and Curtis, J.S., 2021, "Discrete element method models of elastic and elasto-plastic fiber assemblies", AIChE Journal, e17296, Vol. 67, No. 8, pp. 1-16. doi: 10.1002/aic.17296.
• Chen, Z., Wassgren, C., and Ambrose, R.P.K., 2021, "Measured damage resistance of corn and wheat kernels to compression, friction, and repeated impacts", Powder Technology, Vol. 380, pp. 638-648. doi: 10.1016/j.powtec.2020.11.012
• Jiang, Y., Guo, Y., Yu, Z., Hua, X, Lin, J-z., Wassgren, C., and Curtis, J.S, 2020, "DEM-CFD analyses of flexible fiber fluidization", Journal of Fluid Mechanics, Vol. 910, A8, doi: 10.1017/jfm.2020.930.
• (video) Chen, Z., Wassgren, C., Veikle, E., and Ambrose, K., 2020, "Determination of material and interaction properties of maize and wheat kernels for DEM simulation", Biosystems Engineering, Vol. 195, pp. 208-226, doi:10.1016/j.biosystemseng.2020.05.007.
• (video) Pardikar, K., Zahid, S., and Wassgren, C., 2020, "Quantitative comparison of experimental and Mohr-Coulomb finite element method simulation flow characteristics from quasi two-dimensional flat-bottomed bins", Powder Technology, Vol. 367, pp. 689-702, doi:10.1016/j.powtec.2020.04.036.
• Liu, Y., Yu, Z., Yang, J., Wassgren, C., Curtis, J.S., and Guo, Y., 2020, "Discrete element method investigations of binary granular flows with different particle shapes", Energies, Vol. 13, pp. 1841 - 1866, doi:10.3390/en13071841. (Open Access)
• (video) Chen, Z., Wassgren, C., and Ambrose, R.P.K., 2020, "Measurements of grain kernel friction coefficients using a reciprocating-pin tribometer", Transactions of the ASABE, Vol. 63, No. 3, pp. 675 - 685, doi: 10.13031/trans.13748.
• Guo, Y., Li, Y., Liu, Q., Jin, H., Xu, D., Wassgren, C., and Curtis, J.S., 2020, "An investigation on triaxial compression of flexible fiber packings", AIChE Journal, Vol. 66, No. 6, e16946, doi: 10.1002/aic.16946.
• Chen, Z., Wassgren, C., and Ambrose, R.P.K., 2020, "A review of grain kernel damage: Mechanisms, modeling, and testing procedures", Transactions of the ASABE, Vol. 63, No. 2, pp. 455 - 475, doi:10.13031/aea.13643.
• Wang, L.G., Pradhan, S.U., Wassgren, C., Barrasso, D., Slade, D., and Litster, J.D., 2020, "A breakage kernel for use in population balance modelling of twin screw granulation", Powder Technology, Vol. 363, pp. 525-540. doi: 10.1016/j.powtec.2020.01.024.
• Pardikar, K. and Wassgren, C., 2019, "Predicting the critical outlet width of a hopper using a continuum finite element method model", Powder Technology, Vol. 356, pp. 649-660. doi: 10.1016/j.powtec.2019.08.111.
• Karkala, S., Davis, N., Wassgren, C., Shi, Y., Liu, X., Riemann, C., Yacobian, G., and Ramachandran, R., 2019, "Calibration of discrete-element-method parameters for cohesive materials using dynamic-yield-strength and shear-cell experiments", Processes, Vol. 7, No. 5, pp. 278 - 294. doi:10.3390/pr7050278. Open Access.
• Kumar, R., Ketterhagen, W., Sarkar, A., Curtis, J.S., and Wassgren, C., 2019, "Breakage modeling of needle-shaped particles using the discrete element method", Chemical Engineering Science X, Vol. 3, Article 100027. doi:10.1016/j.cesx.2019.100027. Open Access.
• Yang, J., Bello, L., Buettner, K., Guo, Y., Wassgren, C., and Curtis, J.S., 2019, "Breakage of wet flexible fiber agglomerates impacting a plane", AIChE Journal, Vol. 65, No. 8, Article e16626. doi: 10.1002/aic.16626.
• Liu, Y., Gonzalez, M., and Wassgren, C., 2019, "Modeling granular material segregation using a combined finite element method and advection-diffusion-segregation equation model", Powder Technology, Vol. 346, pp. 38 - 48. doi:10.1016/j.powtec.2019.01.086.
• Li, J., Pradhan, S., and Wassgren, C., 2019, "Granule transformation in a twin screw granulator: Effects of conveying, kneading, and distributive mixing elements", Powder Technology, Vol. 346, pp. 363 - 372. doi:10.1016/j.powtec.2018.11.099.
• Liu, Y., Cameron, A.T., Gonzalez, M., and Wassgren, C., 2018, "Modeling granular material blending in a Tote blender using a finite element method and advection-diffusion equation multi-scale model", Powder Technology, Vol. 340, pp. 428 - 439, doi: 10.1016/j.powtec.2018.09.033.
• Cameron, A.T., Liu, Y., Wassgren, C., and Gonzalez, M., 2018, "Granular material mixing: Experiments for calibration and validation", Journal of Purdue Undergraduate Research, Vol. 8, pp. 2 - 9.
• Guo, Y., Buettner, K., Lane,V., Wassgren, C., Ketterhagen, W., Hancock, B., and Curtis, J., 2019, "Computational and experimental studies of flexible fiber flows in a normal-stress-fixed shear cell", AIChE Journal, Vol. 65, No. 1, pp. 64 - 74. doi:10.1002/aic.16397.
• Pradhan, S.U., Sen, M., Li, J., Gabbott, I., Reynolds, G., Litster, J.D., and Wassgren, C.R., 2018, "Characteristics of multi-component formulation granules formed using distributive mixing elements in twin screw granulation", Drug Development and Industrial Pharmacy, Vol. 44, No. 11, pp. 1826 - 1837, doi: 10.1080/03639045.2018.1503293.
• Issa, S., Wassgren, C., Schwab, C., Stroshine, R., and Field, W., 2018, "Estimating passive stress acting on a grain entrapment victim's chest", Journal of Agricultural Safety and Health, Vol. 24, No. 3, pp. 113 - 126, doi: 10.13031/jash.12552. Received a 2018 ASABE Superior Paper award.
• Liu, Y., Gonzalez, M., and Wassgren, C., 2018, "Modeling granular material blending in a rotating drum using a finite element method and advection-diffusion equation multi-scale model", AIChE Journal, Vol. 64, No. 9, pp. 3277 - 3292.
• Guo, Y., Wassgren, C., Ketterhagen, W., Hancock, B., and Curtis, J.S., 2018, "Discrete element simulation studies of angle of repose and shear flow of wet, flexible fibers", Soft Matter, Vol. 14, pp. 2923 - 2937, doi: 10.1039/C7SM02135F.
• Kumar, R., Sarkar, A., Ketterhagen, W., Hancock, B., Curtis, J., and Wassgren, C., 2018, "Influence of normal contact force model on simulations of sphero-cylindrical particles", AIChE Journal, Vol. 64, No. 6, pp. 1986 - 2001.
• Pradhan, S.U., Zhang, Y., Li, J., Litster, J.D., and Wassgren, C.R., 2018, "Tailored granule properties using 3D printed screw geometries in twin screw granulation", Powder Technology, Vol. 341, pp. 75 - 84. doi: 10.1016/j.powtec.2017.12.068.
• Guo, Y., Wassgren, C., Curtis, J.S., and Xu, D., 2018, "A bonded sphero-cylinder model for the discrete element simulation of elasto-plastic fibers", Chemical Engineering Science, Vol. 175, pp. 118-129. doi: 10.1016/j.ces.2017.09.029.
• Ban, J., Kumar, R., Agarwal, S., and Wassgren, C, 2017, "Scaling inter-tablet coating variability in a horizontal rotating drum", AIChE Journal, Vol., 63, No. 9, pp. 3743-3755, doi: 10.1002/aic.15758.
• Pradhan, S.U., Sen, M., Li, J., Litster, J.D., and, Wassgren, C.R., 2017, "Granule breakage in twin screw granulation: Effect of material properties and screw element geometry", Powder Technology, Vol. 315, pp. 290-299, doi:10.1016/j.powtec.2017.04.011.
• Swaminathan, S., Ramey, B., Hilden, J., and Wassgren, C., 2017, "Characterizing the powder punch-face adhesive interaction during the unloading phase of powder compaction", Powder Technology, Vol. 315, pp. 410-421, doi:10.1016/j.powtec.2017.04.003.
• Guo, Y., Wassgren, C., Hancock, B., Ketterhagen, W., and Curtis, J., 2017, "Predicting breakage of high aspect ratio particles in an agitated bed using the discrete element method", Chemical Engineering Science, Vol. 158, pp. 314 - 327.
• Swaminathan, S., Hilden, J., Ramey, B., and Wassgren, C., 2016, "Modeling the formation of debossed features on a pharmaceutical tablet", Journal of Pharmaceutical Innovation, Vol. 11, No. 3, pp. 214 - 230.
• Dosta, M., Dale, S., Antonyuk, S., Wassgren, C.R., Heinrich, S., and Litster, J.D., 2016, "Numerical and experimental analysis of influence of granule microstructure on its compression breakage", Powder Technology, Vol. 299, pp. 87 - 97.
• Liu, Y. and Wassgren, C., 2016, "Modifications to Johanson's roll compaction model for improved relative density predictions", Powder Technology, Vol. 297, pp. 294 - 302.
• Khola, N. and Wassgren, C., 2015, "Correlations for shear-induced percolation segregation in granular shear flows", Powder Technology, Vol. 288, pp. 441 - 452.
• Mort, P., Michaels, J.N., Behringer, R.P., Campbell, C.S., Kondic, L., Kheiripour Langroudi, M., Shattuck, M., Tang, J., Tardos, G.I., and Wassgren, C., 2015, "Dense granular flow - A collaborative study", Powder Technology, Vol. 284, pp. 571 - 584.
• Hua, X., Curtis, J., Hancock, B., Ketterhagen, W., and Wassgren, C., 2015, "The internal loads, moments, and stresses in rod-like particles in a low-speed, vertical axis mixer", Chemical Engineering Science, Vol. 134, pp. 581-598.
• Freireich, B., Kumar, R., Ketterhagen, W., Su, K., Wassgren, C., and Zeitler, J.A., 2015, "Comparisons of intra-tablet coating variability using DEM simulations, asymptotic limit models, and experiments", Chemical Engineering Science, Vol. 131, pp. 197-212. (Open Access)
• Anand, A., Curtis, J., Wassgren, C., Hancock, B., and Ketterhagen, W., 2015, "Experimental study of wet cohesive particles discharging from a rectangular hopper", Industrial & Engineering Chemistry Research, Vol. 54, No. 16, pp. 4545-4551.
• Sarkar, A. and Wassgren, C., 2015, "Effect of particle size on flow and mixing in a bladed granular mixer", AIChE Journal, Vol. 61, No. 1, pp. 46 - 57.
• Kumar, R., Freireich, B., and Wassgren, C., 2015, "DEM-compartment-population balance model for particle coating in a horizontal rotating drum", Chemical Engineering Science, Vol. 125, pp. 144-157.
• Dale, S., Wassgren, C., and Litster, J., 2014, "Measuring granule phase volume distributions using x-ray microtomography", Powder Technology, Vol. 264, pp. 550-560.
• Kumar, R. and Wassgren, C., 2014, "Inter-particle coating variability in a continuous coater", Chemical Engineering Science, Vol. 117, pp. 1-7.
• Guo, Y., Wassgren, C., Ketterhagen, W., Hancock, B., and Curtis, J., 2013, "Validation and time step determination of discrete element modeling of flexible fibers", Powder Technology, Vol. 249, pp. 386-395.
• Wang, T., Alston, K.M., Wassgren, C.R., Mockus, L., Catlin, A.C., Fernando, S.R., Fernando, S., Basu, P.K., and Hoag, S.W., 2013, "The creation of an excipient properties database to support Quality by Design (QbD) formulation development", American Pharmaceutical Review, Vol. 16, No. 4, pp. 16-25.
• Barraso, D., Oka, S., Muliadi, A., Litster, J.D., Wassgren, C., and Ramachandran, R., 2013, "Population balance model validation and prediction of CQAs for continuous milling processes: Toward QbD in pharmaceutical drug product manufacturing", Journal of Pharmaceutical Innovation, Vol. 8, No. 3, pp. 147-162.
• Guo, Y., Wassgren, C., Hancock, B., Ketterhagen, W., and Curtis, J., 2013, "Granular shear flows of flat disks and elongated rods without and with friction", Physics of Fluids, Vol. 25, Article 06334.
• Hua, X., Curtis, J., Hancock, B., Ketterhagen, W., and Wassgren, C., 2013, "The kinematics of non-cohesive, sphero-cylindrical particles in a low-speed, vertical axis mixer", Chemical Engineering Science, Vol 101, pp. 144 - 164.
• Li, J., Wassgren, C., and Litster, J.D., 2013, "Multi-scale modeling of a spray coating process in a paddle mixer/coater: The effect of particle size distribution on particle segregation and coating uniformity", Chemical Engineering Science, Vol. 95, pp. 203 - 210.
• Kumar, R. and Wassgren, C., 2013, "Angular circulation speed of tablets in a vibratory tablet coating pan", AAPS PharmSciTech, Vol. 14, No. 1, pp. 339 - 351.
• Muliadi, A., Wassgren, C., and Litster, J., 2012, "Validation of 3-D finite element analysis for predicting the density distribution of roll compacted pharmaceutical powder", Powder Technology, Vol. 237, pp. 386 - 399.
• Guo, Y., Wassgren, C., Ketterhagen, W., Hancock, B., Benjamin, J., and Curtis, J., 2012, "A numerical study of granular shear flows of rod-like particles using the discrete element method", Journal of Fluid Mechanics, Vol. 713, pp. 1 - 26.
• Guo, Y., Wassgren, C., Ketterhagen, B., Hancock, B., and Curtis, J., 2012, "Some computational considerations associated with discrete element modeling of cylindrical particles", Powder Technology, Vol. 228, pp. 193 - 198.
• Kayrak-Talay, D., Dale, S., Wassgren, C., and Litster, J., 2012, "Quality by design for wet granulation in pharmaceutical processing: Assessing models for a priori design and scaling", Powder Technology, Vol. 240, pp. 7 - 18.
• Sarkar, A. and Wassgren, C.R., 2012, "Comparison of flow microdynamics for a continuous granular mixer with predictions from periodic slice DEM simulations", Powder Technology, Vol. 221, pp. 325-336.
• Li, J., Freireich, B.J., Wassgren, C.R., and Litster, J., 2013, "Experimental validation of a 2-D population balance model for spray coating processes", Chemical Engineering Science, Vol. 95, pp. 360 - 365.
• Muliadi, A., Wassgren, C., and Litster, J., 2012, "Modeling the powder roll compaction process: Comparison of 2-D finite element method and the rolling theory for granular solids (Johanson's model)", Powder Technology, Vol. 221, pp. 90 - 100.
• Kodam, M., Curtis, J., Hancock, B., and Wassgren, C., 2012, "Discrete element method modeling of bi-convex pharmaceutical tablets: Contact detection algorithms and validation", Chemical Engineering Science, Vol. 69, No. 1, pp. 587 - 601.
• Rao, A., Hancock, B., Wassgren, C., and Curtis, J.S., 2011, "Numerical simulation of dilute turbulent gas-particle flow with turbulence modulation", AIChE Journal, Vol. 58, No. 5, pp. 1381-1396.
• Li, J., Freireich, B., Wassgren, C., and Litster, J., 2011, "A general compartment-based population balance model for particle coating and layered granulation", AIChE Journal, Vol. 58, No. 5, pp. 1397-1408.
• Freireich, B., Li, J., Litster, J., and Wassgren, C., 2011, "Incorporating particle flow information from discrete element simulations in population balance models of mixer-coaters", Chemical Engineering Science, Vol. 66, No. 16, pp. 3592-3604.
• Freireich, B., Ketterhagen, W.R., and Wassgren, C., 2011, "Intra-tablet coating variability for several pharmaceutical tablet shapes", Chemical Engineering Science, Vol. 66, No. 12, pp. 2535-2544.
• Dubey, A., Sarkar, A., Ierapetritou, M., Wassgren, C.R., and Muzzio, F.J., 2011, "Computational approaches for studying the granular dynamics of continuous blending processes, 1-DEM based methods", Macromolecular Materials and Engineering, Vol. 296, Nos. 3-4, pp. 290-307.
• Kodam, M., Bharadwaj, R., Curtis, J., Hancock, B., and Wassgren, C., 2010, "Cylindrical object contact detection for use in discrete element method simulations. Part II: Experimental Validation", Chemical Engineering Science, Vol. 65, No. 22, pp. 5863-5871.
• Kodam, M., Bharadwaj, R., Curtis, J., Hancock, B., and Wassgren, C., 2010, "Cylindrical object contact detection for use in discrete element method simulations. Part I: Contact detection algorithms", Chemical Engineering Science, Vol. 65, No. 22, pp. 5852-5862.
• Rao, A., Curtis, J.S., Hancock, B.C., and Wassgren, C., 2010, "Classifying the fluidization and segregation behavior of binary mixtures using particle size and density ratios", AIChE Journal, Vol. 57, No. 6, pp. 1446-1458.
• Dechelette, A., Sojka, P.E., and Wassgren, C.R., 2010, "Non-Newtonian drops spreading on a flat surface", Journal of Fluids Engineering, Vol. 132, No. 10, Article 101302.
• Sarkar, A. and Wassgren, C., 2010, "Continuous blending of cohesive granular material", Chemical Engineering Science, Vol. 65, No. 21, pp. 5687-5698.
• Sinha, T., Curtis, J.S., Hancock, B.C., and Wassgren, C., 2010, "Finite element analysis of pharmaceutical tablet compaction using a density dependent material plasticity model", Powder Technology, Vol. 202, Nos. 1-3, pp. 46-54.
• Sinha, T., Curtis, J.S., Hancock, B.C., and Wassgren, C., 2010, "A study on the sensitivity of Drucker-Prager Cap model parameters during the decompression phase of powder compaction simulations", Powder Technology, Vol. 198, No. 3, pp. 315-324.
• Anand, A., Curtis, J.S., Wassgren, C.R., Hancock, B.C., and Ketterhagen, W.R., 2010, "Segregation of cohesive granular materials during discharge from a rectangular hopper", Granular Matter, Vol. 12, pp. 193-200.
• Freireich, B., Kodam, M., and Wassgren, C., 2010, "An exact method for determining local solid fractions in discrete element method simulations", AIChE Journal, Vol. 56, No. 12, pp. 3036-3048.
• Rao, A., Curtis, J.S., Hancock, B., and Wassgren, C., 2010, "The effect of column diameter and bed height on minimum fluidization velocity", AIChE Journal, Vol. 56, No. 9, pp. 2304-2311.
• Freireich, B. and Wassgren, C., 2010, "Intra-particle coating variability: Analysis and Monte-Carlo simulations", Chemical Engineering Science, Vol. 65, pp. 1117-1124.
• Anand, A., Curtis, J.S., Wassgren, C.R., Hancock, B.C., and Ketterhagen, W.R., 2009, "Predicting discharge dynamics of wet cohesive particles from a rectangular hopper using the discrete element method (DEM)", Chemical Engineering Science, Vol. 64, No. 24, pp. 5268-5275.
• Ketterhagen, W.R., Curtis, J.S., Wassgren, C.R., and Hancock, B.C., 2009, "Predicting the flow mode from hoppers using the discrete element method", Powder Technology, Vol. 195, No. 1, pp. 1-10.
• Kodam, M., Bharadwaj, R., Curtis, J.S., Hancock, B.C., and Wassgren, C., 2009, "Force model considerations for glued sphere discrete element method simulations", Chemical Engineering Science, Vol. 64, No. 15, pp. 3466-3475.
• Freireich, B., Litster, J., and Wassgren, C., 2009, "Using the discrete element method to predict collision-scale behavior: A sensitivity analysis", Chemical Engineering Science, Vol. 64, No. 15, pp. 3407-3416.
• Kalbag, A. and Wassgren, C., 2009, "Inter-tablet coating variability: Tablet residence time variability", Chemical Engineering Science, Vol. 64, pp. 2705-2717.
• Sarkar, A. and Wassgren, C.R., 2009, "Simulation of a continuous granular mixer: Effect of operating conditions on flow and mixing", Chemical Engineering Science, Vol. 64, pp. 2672-2682.
• Anand, A., Curtis, J.S., Wassgren, C.R., Hancock, B.C., and Ketterhagen, W.R., 2008, "Predicting discharge dynamics from a rectangular hopper using the discrete element method (DEM)", Chemical Engineering Science, Vol. 63, pp. 5821-5830.
• Feng, T., Wang, F., Pinal, R., Wassgren, C., and Carvajal, M.T., 2008, "Investigation of the variability of NIR in-line monitoring of roller compaction process by using fast Fourier transform (FFT) analysis", AAPS PharmSciTech., Vol. 9, No. 2, pp. 419-424.
• Kalbag, A., Wassgren, C., Penumetcha, S.S., and Perez-Ramos, J.D., 2008, "Inter-tablet coating variability: Residence times in a horizontal pan coater", Chemical Engineering Science, Vol. 63, No. 11, pp. 2881-2894.
• Ketterhagen, W.R., Curtis, J.S., Wassgren, C.R., and Hancock, B.C., 2008, "Modeling granular segregation in flow from quasi-three-dimensional wedge-shaped hoppers", Powder Technology, Vol. 179, pp. 126-143.
• Pederson, B.M., Sadeghi, F., and Wassgren, C., 2007, "The effects of cage flexibility on ball-to-cage pocket contact forces and cage instability in deep groove ball bearings", SAE 2006 Transactions Journal of Passenger Cars: Mechanical Systems, Paper No. 2006-01-0358, pp. 260-271.
• Ketterhagen, W.R., Curtis, J.S., Wassgren, C.R., Kong, A., Narayan, P.J., and Hancock, B.C., 2007, "Granular segregation in discharging cylindrical hoppers: A discrete element and experimental study", Chemical Engineering Science, Vol. 62, pp. 6423-6439.
• Wassgren, C. and Curtis, J.S., 2006, "The application of computational modeling to pharmaceutical materials science", MRS Bulletin, Vol. 31, No. 11, pp. 900-904.
• Bharadwaj, R., Wassgren, C., and Zenit, R., 2006, "The unsteady drag force on a cylinder immersed in a dilute granular flow", Physics of Fluids, Vol. 18, Art. 043301.
• Duncan, M.R., Wassgren, C.R., and Krousgrill, C.M., 2005, "The damping performance of a single particle impact damper", Journal of Sound and Vibration, Vol. 286, pp. 123-144.
• Ketterhagen, W.R., Curtis, J.S., and Wassgren, C.R., 2005, "Stress results from two-dimensional granular shear flow simulations using various collision models", Physical Review E, Vol. 71, Art. 061307.
• Ghaisas, N., Wassgren, C.R., and Sadeghi, F.A., 2004, "Cage instabilities in cylindrical roller bearings", Journal of Tribology, Vol. 126, No. 4, pp. 681-689.
• Arroyo-Cetto, D., Pulos, G., Zenit, R., Jimenez-Zapata, M.A., and Wassgren, C.R., 2003, "Compaction force in a confined granular column", Physical Review E, Vol. 68, Art. 051301.
• Fernando, D. and Wassgren, C., 2003, "Effects of vibration method and wall boundaries on size segregation in granular beds", Physics of Fluids, Vol. 15, No. 11, pp. 3458-3467.
• Wassgren, C.R., Cordova, J.A., Zenit, R., and Karion, A., 2003, "Dilute granular flow around an immersed cylinder", Physics of Fluids, Vol. 15, No. 11, pp. 3318-3330.
• Chehata, D., Zenit, R., and Wassgren, C.R., 2003, "Dense granular flow around an immersed cylinder", Physics of Fluids, Vol. 15, No. 6, pp. 1622-1631.
• Park, J. and Wassgren, C., 2003, "Modeling the dynamics of fabric in a rotating horizontal drum using the discrete element method", International Journal of Particulate Science and Technology, Vol. 21, No. 2, pp. 157-175.
• Aphale, A., Bolander, N., Park, J., Shaw, L., Svec, J., and Wassgren, C., 2003, "Granular fertilizer particle dynamics on and off a spinner spreader", Biosystems Engineering, Vol. 85, No. 3, pp. 319-329.
• Wassgren, C.R., Hunt, M.L., Freese, P.J., Palamara, J., and Brennen, C.E., 2002, "Effects of vertical vibration on hopper flows of granular material", Physics of Fluids, Vol. 14, pp. 3439-3448.
• Shishodia, N. and Wassgren, C., 2001, "Buoyancy effects in vibro-fluidized beds", Physical Review Letters, Vol. 87, Article 084302. Shishodia, N. and Wassgren, C., 2002, "Erratum: Buoyancy effects in vibro-fluidized beds", Physical Review Letters, Vol. 88, Article 109901(E).
• Hunt, M.L., Weathers, R.C., Lee, A.T., Brennen, C.E., and Wassgren, C.R., 1999, "Effects of horizontal vibration on hopper flows of granular materials", Physics of Fluids, Vol. 11, No. 1, pp. 68-75.
• Wassgren, C.R., Brennen, C.E., and Hunt, M.L., 1996, "Vertical vibration of a deep bed of granular material in a container", Journal of Applied Mechanics, Vol. 63, pp. 712-719.
• Brennen, C.E., Ghosh, S., and Wassgren, C.R, 1996, "Vertical oscillation of a bed of granular material", Journal of Applied Mechanics, Vol. 63, pp. 156-161.
• Su, G.W., Choi, D.U., Drean, R.J., Edelsohn, C.R., Gurley, J.G., Hagen, F.A., Landecker, P.B., Tillman, M.L., and Wassgren, C.R., 1993, "Engineering challenges for unmanned lunar exploration", Space Technology, Vol. 13, No. 4, pp. 395-401.
• Burton, R.L and Wassgren, C., 1992, "Time-critical low-thrust orbit transfer optimization", Journal of Spacecraft and Rockets, Vol. 29, No. 2, pp. 286-288. doi: 10.2514/3.25464