Qualification:
Ph.D, M.Tech, B-Tech
Email:
anillals@am.amrita.edu

Dr. Anil Lal S. currently serves as a Professor in the Department of Mechanical Engineering at the School of Engineering, Amrita Vishwa Vidyapeetham, Amritapuri from July 1, 2021, onwards. His research interests include Fluid Dynamics, Heat Transfer, Computational Fluid Dynamics, FEM, FVM, Statistics, Economics and Mathematics. He received B. Tech in Mechanical Engineering from University of Kerala (TKM College of Engineering, Kollam) in 1987; M.Tech in Turbomachines from IIT Madras in January 1996; Ph.D. in Turbomachines from IIT Madras in April 2002. He also passed MA Economics in First Division from IGNOU in the December 2020 examination.  He had successfully completed a one-year orientation course in Nuclear Science and Engineering from BARC training school (31st batch during 1987-88) and served as a scientific officer at Indira Gandhi Center for Atomic Research (IGCAR), Kalpakkam from August 1988 to March 1992. He has over 29 years of teaching experience at Government Engineering Colleges in Kerala before joining Amrita School of Engineering. He was Head of Mechanical Engineering Departments at Govt. Engineering College, Barton Hill and College of Engineering, Trivandrum. He has served as the PG Dean of Govt. Engineering College, Barton Hill for about 3 years.  He was Dean, Faculty of Engineering and Technology at the University of Kerala from May 2019- May 2021. He has authored two textbooks: Advanced Mechanics of Solids (ISBN: No. 978-80-85-955-35-4) and Calculus (ISBN: No. 978-81-933029-1-0) and coordinator of funded sponsored projects of about one crore.

He has successfully guided 5 candidates for their Ph.D. and examination on 2 Ph.D. thesis is in progress.  He has 30 Publications in International Journals and over 35 International conferences.

## Publications

### Publication Type: Journal Article

Year of Publication Title

2021

A. Jayakrishnan and Dr. Anil Lal S., “Assessing the Practicability of the Condition used for Dynamic Equilibrium in Pasinetti Theory of Distribution”, ARXIV: arXiv:2104.05229v1 , 2021.[Abstract]

In this note an assessment of the condition $$K_w/K=S_w/S$$ is made to interpret its meaning to the Passineti's theory of distribution\cite{pasinetti1962rate}. This condition leads the theory to enforce the result $$s_w\rightarrow0$$ as $$P_w\rightarrow 0$$, which is the Pasinetti's description about behavior of the workers. We find that the Pasinetti's claim, of long run worker's propensity to save as not influencing the distribution of income between profits and the wage can not be generalized. This claim is found to be valid only when $$W>>P_w$$ or $$P_w=0$$ with $$W\ne0$$. In practice, the Pasinetti's condition imposes a restriction on the actual savings by one of the agents to a lower level compared to its full saving capacity. An implied relationship between the propensities to save by workers and capitalists shows that the Passineti's condition can be practiced only through a contract for a constant value of $$R=s_w/s_c$$, to be agreed upon between the workers and the capitalists. It is showed that the Passineti's condition can not be described as a dynamic equilibrium of economic growth. Implementation of this condition (a) may lead to accumulation of unsaved income, (b) reduces growth of capital, (c)is not practicable and (d) is not warranted. We have also presented simple mathematical steps for the derivation of the Pasinetti's final equation compared to those presented in \cite{pasinetti1962rate}

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2021

Dr. Anil Lal S. and S, A. Kumar, “Effects of Prandtl Number on Three Dimensional Coherent Structures in the Wake behind a Heated Cylinder”, Journal of Applied Fluid Mechanics, vol. 14, pp. 515-526, 2021.[Abstract]

Flow past a heated cylinder kept at constant surface temperature is computationally simulated and analyzed in the laminar regime at moderate buoyancy. In this study, we have restricted to moderate Reynolds numbers to completely eliminate the presence of mode-A and mode-B instabilities. The three dimensional transition due to the mode E instability is captured using a cell-centered finite volume method. The present study reveals the existence of two different kinds of coherent structures-the "surface plumes" and the "mushroom structures". The role of these mushroom structures in the heat transfer mechanism and the changes that the Prandtl number would bring into this coherent structure are discussed. The mushroom structures observed show high dependency on the changes in Prandtl number whereas the surface plumes are found almost unaffected.

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2021

Dr. Anil Lal S., S M, S., and Pai, A. S., “Numerical Analysis for the Assessment of Factors Influencing the Breakdown of Swirl Flow in a Cylinder Driven by a Rotating End Wall”, ASME Journal of Fluids Engineering , vol. 143, no. 2, p. 021302 , 2021.[Abstract]

Finite element solution for the classical problem of swirl flow in a cylinder with a rotating lid has been used to study the characteristic features of the stream-tube and identify the factors contributing to axial vortex breakdown. An increase of rotational Reynolds number has been found to result in (i) a decrease of total flow rate; (ii) an increase of flow rate through the boundary layer over the stationary walls; (iii) an increase of the throat area of the stream-tube, with the upstream axial vortex flow in some cases having a deficit in momentum flux needed to overcome the pressure and viscous forces; and (iv) an increase of distance for the axial flow to sustain deceleration in the diverging passage. Based on the analysis, it is hypothesized that “flow with particles in axial vortex motion having a deficit of momentum flux for axial flow when subjecting to a fluctuating radial force undergoes axial vortex breakdown.” This explanation has been able to justify the disappearance of vortex breakdown at larger Re of laminar regime and the absence of vortex breakdown in small aspect ratio cylinders. We report novel results pertaining to total flow rate and its distribution within the vessel. The momentum flux of axial vortex, a main determinant of bubble breakdown, is found to be governed by the total flow rate, distribution of flow through the boundary layers, and the Reynolds number. The proposed hypothesis has been verified by analyzing two cases, one involving a passive and the other involving an active mechanism for regulating the axial momentum.

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2021

Dr. Anil Lal S. and Abraham, A. Mathew, “Optimization of a Draft Tube Design Using Surrogate Modelling and Genetic Algorithm”, Journal of The Institution of Engineers (India): Series C, Springer, 2021.[Abstract]

A surrogate-model-based design optimization methodology using Genetic Algorithm to maximize the Static Pressure Rise (SPR) in conical draft tubes is presented. A set of accurate and computationally intensive data obtained from ANSYS-CFD simulations on space filling samples is used for developing a surrogate model. The methodology uses (i) A Latin hypercube experimental design for selecting space filling samples, (ii) Genetic Algorithm for determining parameters of a radial basis function based Kriging model formulated as minimization of a negative log-likelihood function and (iii) length of the straight portion (L), angle of divergence (αd) and inlet swirl angle (αsw) of draft tube as explanatory variables. Flow in the draft tube is characterized by the presence of wall separation, recirculation and axial vortex rope occurring under different inlet swirl and angle of divergence. The study shows that a flow consisting of a low intensity axial vortex rope near the exit of the draft tube is desirable for better distribution of flow in the radial direction for preventing the wall separation and recirculation in high area ratio draft tubes. It is found that the design variable that controls the development and structure of axial vortex rope is the inlet swirl. Verification using CFD analysis showed that the process of optimization has been able to fine-tune the inlet swirl angle that facilitated an optimum sized vortex rope at the center to cause uniform exit axial velocity and improved flow diffusion without wall separation, resulting in significant improvement in Static Pressure Rise.

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2021

R. Abhilash, Kim, K. - Y., and Dr. Anil Lal S., “Topological Investigation of Junction Flow Between Cylinder and Flat Plate”, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, p. 09544062211000767, 2021.[Abstract]

The paper presents a numerical investigation on the junction flow occurring at the intersection between a wall and a protruding circular cylinder. Simulations of flow for Reynolds number (Re) in the range [125 - 20000] have been carried out using OpenFOAM, an open source CFD tool. Plots of stream tracers have been used to qualitatively characterize the flow topology as either attachment or separation based on the type of singular points, classified as nodes and saddle points. Quantitative variations of momentum flux have been applied to identify a key mechanism for the transition of topology using the relative momentum strength of the incoming and reverse flow. Effect of a thinner boundary layer has been assessed by (i) imposing a reduced wall shear stress, and (ii) increasing the Reynolds number. Features of a typical unsteady flow, in the transition regime, at Re = 20000 have been predicted using Large Eddy Simulation (LES) with a one-equation eddy viscosity sub-grid scale model. Description of the time evolution of the topology at Re = 20000 has been able to validate the one-equation model in OpenFoam as well as to further validate the key mechanism identified for topology transition.

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