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Summer school at CISM, Udine, Italy during 21-25 May, 2018 CISM Summer School 2018.pdf

Symposium proceedings on "Advances in Computation, Modeling and Control of Transitional and Turbulent Flows." is published by World Scientific Publishing Company, Singapore. Link of Book.


New Book titled "Theoretical and Computational Aerodynamics" is published by John Wiley Press. Book Review.


"High Accuracy Computing Methods: Fluid Flows and Wave Phenomena" is published by Cambridge University Press. http://www.cambridge.org/9781107023635


"Instabilities of Flows and Transition to Turbulence" is published by CRC Press/ Taylor & Francis. http://www.crcpress.com/product/isbn/9781439879443


Monograph titled "Instabilities of Flow: with and without Heat Transfer and Chemical Reaction" is published by Springer Wien-New York.
http://link.springer.com/book/10.1007%2F978-3-7091-0127-8


Textbook titled "Fundamentals of CFD" published by Universities Press, Hyderabad, India. "CFD Book Review"

"International Conference On Metacomputing"

Keynote talk at National Institute of Oceanography, Dona Paula, Goa on December 17 2010 by Mr. Swagata Bhaumik.

"National Symposium on HPC in Academia and Beyond"

TALK at BESU, Shibpur, Kolkata on March 4 2010 by Prof. T.K. Sengupta.

MIT PRESENTATIONS (click on the links below)

PLENARY TALK on DNS by Prof T.K. Sengupta at 5th M.I.T Conf. on Advances in CFD (2009).

ICOMEC-2011 Presentation on DNS in CFD by Prof. T. K. Sengupta, S. Bhaumik and Y. G. Bhumkar

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Announcements related to HPCL

Summer school at CISM, Udine, Italy successfully conducted during 21-25 May, 2018 on "High-Performance Computing of Big Data for Turbulence and Combustion" (Co-organizers: Sergio Pirozzoli and Tapan K. Sengupta)

Visitors in 2018 to HPCL: Sahil Bhola (Thapar Institute) for his thesis, Tanay Kanungo (NIT Trichy), Ashwin Joseph Mathews (NIT Calicut) as summer interns. Prof. Bhaumik (IIT Jammu) is spending the summer with us.

Visitors in 2017 to HPCL: Krishna Chand Avatar spent as a semester long intern (January to May), Lucas Lestandi, Raman-Charpak Fellow (Univ. of Bordeaux, France). Arijit Upadhyay from NIT Trichy as summer intern. Photo

HPCL has moved to Western Lab. The aerospace building is going to be taken down to make room for a multi-story building. TKS along with Prof. S. Amiroudine of Univ. of Bordeaux have organized a workshop in Bordeaux on Advances in Fluid Mechanics. About thirty eminent scientists from both the countries made presentations during 11-13 September, 2017. This is being supported by CEFIPRA.

Group photograph on 9th June 2017. Group photograph

We have alerted users of Adams-Bashforth method for the persistent problem of numerical spurious mode and focusing. People who continue to use it are plain dishonest! The role of spurious numerical mode which appears in all three-time level methods has been discussed in the following paper: AMC.pdf
Following audio-slide is for those who wants to see the catastrophic breakdown of solution by the spurious mode. Here third order upwind scheme is used with Adams-Bashforth method. Rest is self-explanatory: AMC Audio slide viewer

Certificate of outstanding contribution in reviewing: Journal of computational physics, awarded July, 2015 to Prof. Tapan K. Sengupta. Certificate of Outstanding Reviewer JCP.pdf

1) Pramodkumar Bagade defended his PhD thesis successfully at IIT Kanpur; 2) Kartikey Asthana has defended his PhD thesis at Stanford University; 3) Jyoti Sangwan defended her M. Tech. thesis on compressibility effects on dynamic stall; 4) Atchyut defended his M. Tech. thesis on reduced order models and 5) Zulqarnain Akbar Shabab defended his M. Tech. thesis on transition by polychromatic excitation. He also investigated the start-up process of excitation on STWF.

Prof. Sengupta was on sabbatical leave during 2015-2016. He has spent three months in Bordeaux during winter; the following summer in Univ. of Cambridge, UK as a Visiting Fellow of Murray-Edwards College and Univ. Engg. Dept, working with Prof. Paul Tucker and his team. Subsequently, he visited Univ. of Bordeaux, as the visiting IDEX Professor in I2M Laboratory, working with Prof. Mejdi Azaiez and others during September and October, 2016.

MHRD sponsored Global Initiative on Academic Network (GIAN) program was held in IIT Bhubaneswar conducted by Profs. Yogesh Bhumkar and Satyanarayana during May 23- June 03, 2016. The speakers were Prof. D. V. Gaitonde (OSU, USA) and Prof. Tapan Sengupta (HPCL, IIT Kanpur).
Title of the course: Computational Acoustics: Engineering and scientific approaches.

Graduating students' farewell at HPCL in 2015. Photo

Book review of Theoretical and Computational Aerodynamics (John Wiley, UK) appeared in Aeronautical Journal of Royal Aeronautical Society. Writing this book was possible with help from all at HPCL.

Transition to turbulence-- the physical mechanism explained in:
Precursor of Transition to Turbulence: spatiotemporal wave front
by: Swagata Bhaumik and Tapan K Sengupta; In: Physical Review E.
PREVIEW LINK: http://spectral.iitk.ac.in/hpcl/LH13761E_25April2014.pdf
Journal link: http://journals.aps.org/pre/accepted/b307fY87Ub91fc3bd7776bb1d6fd45e9cb1...
Recent developments announced in the IUTAM SYMPOSIUM URL: http://spectral.iitk.ac.in/hpcl/IUTAM2014


Third International Conference on Meta Computing 2012, held in Bhubaneswar. Conference Co-Chair: Prof. Tapan K Sengupta Best papers: Drs. V. Mudkavi/ K. Venkatesh (NAL Bangalore) and Pramod Bagade/ B. Satish (IIT Kanpur)


DNS of Transition and Turbulence in Physical Review Letters - see link (1) below.
Also the paper: "Direct numerical simulation of two-dimensional wall-bounded turbulent flows
from receptivity stage" February 2012, Physical Review E (Vol.85, No.2):
URL: http://link.aps.org/doi/10.1103/PhysRevE.85.026308
Related links :
(1) http://prl.aps.org/abstract/PRL/v107/i15/e154501
(2) http://prl.aps.org/abstract/PRL/v96/i22/e224504
(3) http://www.sciencedirect.com/science/article/pii/S0021999107002537

News

    We had two visitors from NITs! Also, Swagata was here for the summer! Suman and Jyothi Kumar have joined HPCL for PhD. Sahil has finished his internship and has done some good work on transonic flow and control. He is from Thapar Institute. Kritikesh has joined us from IISER Pune, with lots of enthusiasm on detecting turbulence! He is working on Rortex. We are making progress in our understanding coherent structure detection techniques. Our disturbance mechanical energy (DME) and disturbance enstrophy transport equation (DETE) hold the key. These two are most physical approach, as opposed to other techniques which can indirectly identify vortex via pressure minimum.

The book/ monograph on DNS of turbulent flow over a flat plate is out as an e-book! It is good that HPCL has taken the initiative to write down in details about what depth one can study the subject. Hopefully, this case study will act as a guide-book for those interested in learning hands-on! So calling on all the well-wishers and participants of HPCL to seize the initiative and get involved in DNS/ ILES!

HPCL has explained FOCUSING - a numerical meltdown faced in diverse fields! The codes that run for very long time, suddenly blow up in a small time interval due to FOCUSING. In 1970's/ 1980's this has been attributed to nonlinear instability, following early works by Phillips and Smagorinsky. Some even attributed it to chaos dynamics. Present work is a follow up research at HPCL with Prof. Sagaut (then at UPMC) to investigate nonlinear numerical instability for a CEFIPRA project. In the project, spectral analysis of scientific computing was developed using 1D convection equation to establish why von Neumann analysis is inadequate [ paper in JCP (2007)]. The Global Spectral Analysis (GSA) has never disappointed! GSA has been used for: 2D Convection equation, diffusion equation, convection-diffusion equation, shallow water equation, KdV equation, bidirectional waves. Many phenomena have been explained, and recently we have explained "focusing"! In Dec. 2014, work on focusing was restarted for 3-time level methods with results in AMC (2017) for 3-time level methods, mainly Adams-Bashforth method. Recent work in Computers and Fluids reestablishes focusing as a linear phenomenon for two time level method. In these examples, focusing is due to anti-diffusion due to discretization of convection terms.

Work at HPCL in 2015: Dr. Manoj Rajpoot, Aditi, Nidhi, Roshan and Prayash Panda started development of compact schemes for non-uniform grids. Paper by Aditi Sengupta and TKS has appeared in JCP (2016) on this. Sixth order scheme by Nidhi Sharma, Aditi Sengupta, Roshan Samuel, Manoj Rajpoot, TK Sengupta has appeared in Computers and Fluids (2017). This should boost research on IBM. We have also reported properties of methods and filters using unstructured grid methods, by GSA.

We have reported accurate results for Rayleigh-Taylor instability by avoiding Boussinesq approximation and Stokes' hypothesis (incorporating bulk viscosity for Navier-Stokes equation). We have published work on non-equilibrium thermodynamic aspect of RTI in our papers: Int. J. of Thermodynamics, Physics of Fluids, and in CPC proceedings.

Emayvarman, Suman and Jyothi Kumar are PhD candidates joining HPCL. Prasanna, Deepak, Netrapal and Shamini are finishing their M. Tech. in 2018. Siva Viknesh is jointly working with Prof. Poddar and TKS on dynamic stall for his MSc by research program.

Other News:
Zulqarnain is in Bangalore; Jyoti has joined Eton, Pune; Atchyut is with Mercedez; Akhil is with Rolls Royce; Ijlal is placed with Airbus. Nilesh is teaching in Pune/ Mumbai. Prasoon and Soumyo are in Georgia Tech. Dynamic stall work of Prasoon is not new in HPCL, but very accurate now. This follows the work of Sreejith and Ashish on developing transonic flow code, which is also modified for Rayleigh-Taylor instability (RTI). Aditi is in Univ. of Cambridge. Nidhi and Roshan have developed a 3D compressible ILES code for 3D RTI. Vikram Singh (2009 BT-MT) has joined Technion for his PhD. Pushpendra Sharma (PhD student) is working on DNS/LES of 3D flows. Deepak is working on rotary oscillation. We are revisiting vortex-induced instability using 3D V-Omega formulation. Varman is working on 3D flow past cylinder. We plan to look at this problem with high accuracy methods. We have also now a vorticity-vector potential code for a working Navier-Stokes solver, a first for us!

Pramod is now senior faculty member in Univ. of Pune; Yogesh leads a team at IIT Bhubaneswar; Dr. A Kameshwar Rao is at IIT Madras (Mech. Engg.); Prof. Manoj T. Nair is at IIST (Thiruvananthapuram); Dr. Sudipta De is at CMERI Durgapur and Prof. K. Venkatasubbaiah is in IIT Hyderabad. Other members of HPCL: Sarthok Sircar (faculty at IIIT Delhi); Anurag Dipankar (Scientist in Singapore). Rajarshi, PhD candidate at UPMC, Paris and Sreejith (PhD candidate at CERFACS, Tolouse). Dr. Vijay Vedula, post-doc in Stanford. Shakti (UIUC, PhD), Dr. Unnikrishnan at OSU, Columbus, Ohio, Ashwin V M (KTH, PhD candidate) and Shriramakrishnan (PhD candidate at Univ. of Texas). Abir and Himansu have left Eaton; Pallavi and Lakshmanan are with GE (?). Dr. Kathikey Asthana is in NY, USA, (PhD, Stanford). Vishal Srivastava (PhD candidate, Univ. of Michigan). Vivek Joshi (Graduate student, Univ. of Michigan).

Following works were presented in 2015: i) Indian Science Congress for an invited talk; ii) Keynote speech in Int. Conf. on Fluid Mechanics at Univ. of Gauhati; iii) JETC Conf. on Thermodynamics in Nancy, France; iv) Keynote speech and contributed paper in Turbulence & Interaction (TI-2015) at Corsica, France; v) Conf. on Computational Physics (CCP-2015) at IIT Gauhati and vi) an Invited talk in SAROD-2015 at VSSC.

    IUTAM symposium on Advances in Computation, Modeling and Control of Transitional and Turbulent Flows held in Goa, India in December, 2014. The details about the proceedings from WSPC is at: http://spectral.iitk.ac.in/hpcl/IUTAM2014

    Paper titled Precursor of transition to turbulence: Spatio-temporal wave front by Dr. Swagata Bhaumik and Tapan Sengupta in Phys. Rev. E explains by DNS the route to turbulence by harmonic wall excitation. Click for paper

    "Diffusion in inhomogeneous flows: Unique equilibrium state in an internal flow," . A major work shows how small scales are created by diffusion for 2D/3D inhomogeneous flows, from Navier-Stokes equation without any assumptions. For 2D flows, this is the only mechanism. For inhomogeneous flows this is, thus, more general than any other existing concepts! See our new work on Taylor-Green vortex in Physics of Fluids (2018) and on Vortex-Induced Instability in Physics of Fluids (2018).

    The book : "Theoretical and Computational Aerodynamics" has been published by Wiley, UK. See the review in Aeronautical Journal of Royal Aeronautical Society, Feb. 2015 issue. Contains chapters on (i) computational aerodynamics, (ii) NLF and transitional flow related to aerodynamics, (iii) transonic aerodynamics and (iv) low Reynolds number unsteady aerodynamics.

    The book: "High Accuracy Computing Methods: Fluid Flows and Wave Phenomena" is published by Cambridge University Press (2013) with an Indian edition available. See:
http://www.cambridge.org/9781107023635

    Swagata Bhaumik's PhD work on transition and turbulence is culmination of contributions by HPCL over the past two decades, starting with the work on Bromwich contour integral methods in early 90's.

    A 40 parts lecture series on Foundations of Scientific Computing taught to IIT Kanpur undergraduate students (2009) is available as NPTEL course. Similar video course on Transition and Turbulence is also available. Ignore the transcription on screen - those were not done by us!

NPTEL Courses:
1. Foundations of Scientific Computing (2009)
http://nptel.ac.in/courses/101104013/
2. Instability and Transition of Fluid Flows (2010)
http://nptel.ac.in/courses/101104015/

    The book: "Instabilities of Flows and Transition to Turbulence" published by CRC Press, Taylor & Francis Group, USA with details in:
http://www.crcpress.com/product/isbn/9781439879443

    Prof. T. K. Sengupta has helped Tata McGraw-Hill for the Indian edition of Fundamentals of Aerodynamics by Prof. J. D. Anderson, augmented with SI Metrication and a chapter on Aerodynamic Research Activities in India written by him.

    Recent trends in HPC at HPCL, IIT Kanpur, Sep 2009: Account of work done in HPCL, IIT Kanpur, on methods for DNS/ LES was displayed in the Workshop on "High Performance Computing in India" in conjunction with "Supercomputing 2009" (SC09), Nov. 14-20, 2009 (USA).

    Issues related to DNS / LES were the central themes of the plenary talk given at 5th M.I.T. conference, Boston, June 2009

1. Three-time level methods like second order Adam-Bashforth schemes are incorrectly used for "DNS". Following papers show that numerical/ spurious mode removes large fraction of initial condition at higher frequencies. Details in HIGH ACCURACY COMPUTING METHOD (CUP, 2013) and the following papers:

a) A Comparative Study of Time Advancement Methods for Solving Navier-Stokes Equations

Dowload comparative study.. paper from springerlink

b) High Accuracy Schemes for DNS and Acoustics

Download the DNS and acoustics paper from springerlink

2. The von Neumann analysis for PDEs has been corrected, with the help of 1D convection equation, diffusion equation and convection-diffusion equation now. See the following papers:

a) Error Dynamics: Beyond von Neumann Analysis -- T.K. Sengupta, A. Dipankar and P. Sagaut, 226, 1211-1218 (2007)
Dowload Error dynamics: Beyond von Neumann analysis paper from Science Direct

b) Error dynamics of diffusion equation: Effects of numerical diffusion and dispersive diffusion -- T.K. Sengupta and A. Bhole, Journal of Computational Physics, vol. 266, pp 240-251 (2014)

c) Spectral analysis of finite difference schemes for convection diffusion equation-- V.K. Suman, Tapan K. Sengupta, C. J.Durga Prasad, K. Surya Mohan, D. Sanwalia, Computers and Fluids, vol. 150, pp 95-114 (2017)