• Experiences

    NIT Trichy India

    National Institute of Technology Tiruchirappalli

    May 2020 - Present

    Assistant Professor
    Department of Mechanical Engineering

     

     

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    Indian Institute of Technology Hyderabad, India

    Jan 2020- May 2020

    Post Doctoral Fellow

    (National PDF under SERB India)

    Research Topic: Force Network formation in granular crystals

    IIT Madras, India

    Indian Institute of Technology Madras, India

    Jan 2019- Jan 2020

    Post Doc Fellow (Jul 2019 - Jan 2020)

    Institute Pre-Doc Fellowship (Jan 2019- Jun 2019)

     

    Research Topic:

    • Packing of spherical granules into slender prismatic cylinders
    • Fusion ceramic breeder: Full-scale analysis through DEM-ANN-FEM coupling  
  • Education

    IIT Madras, India

    Indian Institute of Technology, Madras

    2014 - 2019

    Doctor of Philosophy

    Thesis on "Numerical Modeling of Mechanical and Thermal Behavior of Pebble Beds in Nuclear Fusion Reactors"

    Mechanics of Materials Lab (MoM Lab)

     

    Master of Science

    (under Dual Degree MS-PhD)

    Dept. of Mechanical Engineering

    CGPA: 8.5/10

     

    BITS

    Birla Institute of Technology and Sciences, Pilani​

    2009 - 2013

    Bachelor of Engineering (B.E. Hons)

    Major: Mechanical Engineering

    CGPA: 9.33/10

     

     

  • Research Areas

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    Granular Mechanics

    A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact. Some examples of granular materials are nuts, coal, sand, rice, corn flakes, and ball bearings. Granular materials are commercially important in applications as diverse as pharmaceutical industry, agriculture, and energy production (Lithium-ion batteries, Solid-oxide fuel cells, and solar thermal energy storage systems). In my research, the main focus on dry granular systems experiencing thermal and mechanical loads.

    DEM (Discrete Element Method)

    The DEM is used to simulate the assembly of particles allowing a finite displacement and rotation of discrete bodies. It is developed based on the idea that discrete particles could be displaced independently from one another and interact with each other only at the contact points. Inter-particle forces are calculated using contact laws. Modeling through DEM has been recently receiving greater attention due to its uniqueness in capturing inter-particle interactions in granular assemblies.

     

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    Thermal DEM

    The estimation of effective thermal conductivity of the granular assemblies is an active area of research dating long back. With the introduction of DEM for the simulation of granular assemblies, estimation of thermal conductivity through contacting pebbles is made possible. The effective thermal conductivity is calculated accounting for the contact conductance between the contacting particles. Resistor-Network model is employed for thermal analysis of granular systems [3].

     

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    Predictive Modelling

    Artificial Neural Networks

    Artificial neural networks (ANN) is one of the widely used machine learning techniques to recognize complex patterns and relationships between inputs and outputs in a system. It learns from processing the data sets to establish a relationship between the inputs and outputs.

    ANN is a computing model whose layered structure resembles the neurological structure in the human brain. It can learn from the data and can be trained to recognize complex patterns, relations and predict. ANN is a collection of connected neurons having a function similar to biological neurons.

    Application of the machine learning techniques to mechanical design as well as in-process predictions for complex systems [1,3,10].

    Publication

    DEM-ANN-FEM

    A hierarchical approach for modeling the thermal response of large-scale granular assemblies by coupling the micro-scale particle-level thermal interactions with the macro-scale continuum system is proposed. The coupling is done by using a machine learning tool that is trained to replicate the effect of discrete particle nature on the macro-scale system using finite elements. A trained Artificial Neural Network (ANN) tool that can estimate the effective local thermal conductivity for each finite element. This way of hierarchical coupling using ANN eliminates the need to perform thermal discrete element simulations for each finite element at every increment by directly predicting the effective local conductivity. The hierarchical approach is applied to a breeder blanket of a fusion reactor that consists of more than 15 million particles to demonstrate the efficacy of the method [1,3].

  • Publications

    Journal Publications

    1. Jaggannagari, Sujith Reddy, Raghuram Karthik Desu, Jörg Reimann, Yixiang Gan, Marigrazia Moscardini, and Ratna Kumar Annabattula. "DEM simulations of vibrated sphere packings in slender prismatic containers." Powder Technology (2021).
    2. Desu, Raghuram Karthik, et al. "Compaction mechanics of a polydisperse crushable spherical granular assembly using discrete element method." International Journal of Advances in Engineering Sciences and Applied Mathematics 13.1 (2021): 114-121.
    3. Desu, Raghuram Karthik, Akhil Reddy Peeketi, and Ratna Kumar Annabattula. "Influence of bed conditions on the effective thermal conductivity of ceramic breeder pebble beds using thermal DEM (TDEM)." Fusion Engineering and Design 159 (2020): 111767.
    4. Peeketi, Akhil Reddy, Desu, Raghuram Karthik, Pramod Kumbhar and Annabattula, Ratna Kumar. "Thermal analysis of large granular assemblies using a hierarchical approach coupling the macro-scale finite element method and micro-scale discrete element method through artificial neural networks." Computational Particle Mechanics 6.4 (2019): 811-822.
    5. Desu, Raghuram Karthik, and Annabattula, Ratna Kumar. "Particle size effects on the contact force distribution in compacted polydisperse granular assemblies" Granular Matter (2019) 21:29.
    6. Desu, Raghuram Karthik, Peeketi Akhil Reddy and Annabattula, Ratna Kumar. "Artificial neural network-based prediction of effective thermal conductivity of a granular bed in a gaseous environment" Computational Particle Mechanics (2019).
    7. Desu, Raghuram Karthik, Paritosh Chaudhuri, and Ratna Kumar Annabattula. "High-temperature oedometric compression of Li2TiO3 pebble beds for Indian TBM." Fusion Engineering and Design (2018).
    8. Desu, Raghuram Karthik, Anand Moorthy, and Ratna Kumar Annabattula. "DEM simulation of packing mono-sized pebbles into prismatic containers through different filling strategies." Fusion Engineering and Design 127 (2018): 259-266.
    9. Desu, Raghuram Karthik, Yixiang Gan, Marc Kamlah, and Ratna Kumar Annabattula. "Mechanics of binary crushable granular assembly through discrete element method." Nuclear Materials and Energy 9 (2016): 237-241.
    10. Desu, Raghuram Karthik, Swadesh Kumar Singh, and Amit Kumar Gupta. "Comparative study of warm and hydromechanical deep drawing for low-carbon steel." The International Journal of Advanced Manufacturing Technology 85, no. 1-4 (2016): 661-672.
    11. Desu, Raghuram Karthik, Hansoge Nitin Krishnamurthy, Aditya Balu, Amit Kumar Gupta, and Swadesh Kumar Singh. "Mechanical properties of austenitic stainless steel 304L and 316L at elevated temperatures." Journal of Materials Research and Technology 5, no. 1 (2016): 13-20.
    12. Desu, Raghuram Karthik, Sharath Chandra Guntuku, B. Aditya, and Amit Kumar Gupta. "Support vector regression based flow stress prediction in austenitic stainless steel 304." Procedia materials science 6 (2014): 368-375.
    13. Gupta, Amit Kumar, Sharath Chandra Guntuku, Desu, Raghuram Karthik, and Aditya Balu. "Optimisation of turning parameters by integrating genetic algorithm with support vector regression and artificial neural networks." The International Journal of Advanced Manufacturing Technology 77, no. 1-4 (2015): 331-339

    Conferences

    • Raghuram Karthik Desu and Ratna Kumar Annabattula*, DEM simulations of packing structures in pebble beds, 19th Ceramic Breeder Blanket Interactions (CBBI-19), Kyoto, Japan, 21-23 September, 2017.
    • Raghuram Karthik Desu* and Ratna Kumar Annabattula, Modeling granular systems with pebble plasticity using discrete element method, Second International Conference on Powder, granule and bulk solids: Innovations and Applications, 1-3 December 2016, Jaipur Rajasthan, India.
    • Raghu Ram Karthik Desu* and Ratna Kumar Annabattula, Modeling granular systems using discrete element method with elasto-plastic contact model, International Workshop on Mechanics of Energy Materials (IWMEM 2016), 14-15 Nov 2016 The University of Sydney, Australia.
    • Raghuram Karthik Desu*, Anand Moorthy and Ratna Kumar Annabattula, Study of packing structures in pebble beds using Discrete Element Method, Second workshop on Lithium ceramics for tritium breeding (LCTB 2016), 23-24 August, 2016.
    • Hirshikesh*, Raghuram Karthik Desu, Ratna Kumar Annabattula and S Natarajan, Mechanics of crushable pebble assembly -- a coupled XFEM-DEM approach, Second workshop on Lithium ceramics for tritium breeding (LCTB 2016), 23-24 August, 2016.
    • Raghuram Karthik Desu*, Ratna Kumar Annabattula, Yixiang Gan and Marc Kamlah, Mechanics of binary crushable pebble assembly, International Conference on Fusion Reactor Materials (ICFRM-17), 11-16 October 2015, Aachen, Germany.
    • Prasad, K. Sajun, Raghuram Karthik Desu, Jayahari Lade, Swadesh Kumar Singh, and Amit Kumar Gupta. "Finite element modeling and prediction of thickness strains of deep drawing using ANN and LS-Dyna for ASS304." In AIP Conference Proceedings, vol. 1567, no. 1, pp. 402-405. AIP, 2013.
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