Here is a poster summarizing my lab's focus.

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.

- 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.

Collaborator(s) |
Affiliation |
Topic |

Jason Ban | Undergraduate researcher (Purdue University) | scaling of pharmaceutical tablet coaters |

Ruixuan Ren | Undergraduate researcher (Purdue University) | liquid movement in pendular liquid bridge formation |

Shrikant Swaminathan | Ph.D. student (Purdue University) | Drucker-Pragar Cap powder property measurements |

Liza Easo | Ph.D. student (Purdue University) | contact spreading of viscous liquids in sheared particulate systems |

Nitan Khola | M.S. student (Purdue University) | inter-particle percolation in sheared systems |

Rohit Kumar | Ph.D. student (Purdue University) | breakage of rod-like particles |

Yu Liu | M.S. student (Purdue University) | powder roll compaction |

Dr. Bill Ketterhagen Dr. Ben Freireich Prof. Axel Zietler |
Pfizer Dow Chemical University of Cambridge |
intra-tablet coating variability |

Sami Labban | U.G. researcher (Purdue University) | continuous coating |

Michael Laska | U.G. researcher (Purdue University) | powder compaction property measurements |

Yuanyuan Xiao | U.G. researcher (Purdue University) | liquid bridge measurements |

Dr. Nha Thai-Quang Prof. Jennifer Curtis Dr. Bruno Hancock Dr. Bill Ketterhagen Dr. Avik Sarkar |
University of Florida University of Florida Pfizer Pfizer Pfizer |
shear flows of cohesive, high aspect ratio, flexible particles |

Dr. Yu Guo Prof. Jennifer Curtis Dr. Bruno Hancock Dr. Bill Ketterhagen |
Jenike and Johanson University of Florida Pfizer Pfizer |
shear flows of high aspect ratio, flexible particles |