Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

Department of Mechanical and Aerospace Engineering

The formation and evolution of counter rotating vortex rings (CRVRs) appearing in shock tube-generated flows at high shock Mach numbers (M) have been studied numerically by solving ax symmetric Navier-Stokes equations and compared with experiments. The AUSM + scheme is used for convective terms, and for time stepping a four-stage Runge-Kutta scheme is used. High-speed smoke flow visualizations and optical shadowgraph techniques are employed for verifying the numerical results. It is observed that the strong shear layer formed near the Mach disc in the axial region of the vortex ring plays a dominant role in CRVR formation. A series of CRVRs is formed for longer driver section and higher M as the shear layer persists for longer duration. The interaction of these CRVRs with the primary vortex and trailing jet vortices is studied for (i) different pressure-pulse durations at the open end keeping the amplitude constant, and (ii) varying pulse amplitude when the duration is fixed. Results are also presented comparing a high-amplitude case against a lower-amplitude one with a longer pulse duration. The maximum vorticity inside the first CRVR is found to be higher than the primary vortex ring during its formation. © 2013 The Japan Society of Fluid Mechanics and IOP Publishing Ltd.

World University root node

Fluid Dynamics Research

A study of the counter rotating vortex rings interacting with the primary vortex ring in shock tube generated flows

Presumed shape multi-environment Eulerian PDF Transport method (MEPDF), which involves representing the joint composition PDF shape as a collection of finite number of Delta functions, has been used to model the turbulence-chemistry interactions. The governing transport equations are solved for the probability and the probability weighted mass fraction of species and enthalpy in an Eulerian frame. The radiation heat transfer is included using the non-gray modeling of the radiative properties of the medium by weighted sum of gray gases (WSGG) considering four fictitious gray gases. The absorption coefficients as well as the weight functions of the gray gases are calculated from published literature as a function of the species mass fraction and temperature. The effect of turbulence radiation interaction (TRI) is included using an empirical relations for emission enhancement. The combined tool is then used to model two pilot stabilized hydrocarbon flames (Sandia Flame D and Delft Flame III) with realistic finite rate chemistry. A parametric study of the micro-mixing constant is performed to understand its impact in flame stabilization. In case of Delft Flame III, two different pilot treatments are considered and also the impact of pilot flame power is studied with the MEPDF model. The current model results have been compared with the experimental data and also with the Lagrangian solution of the joint composition PDF transport equation. The discrepancies of the current predictions with the experimental data and other published results have been quantified and discussed. © 2012 The Combustion Institute.

Combustion and Flame

A numerical investigation of the Eulerian PDF transport approach for modeling of turbulent non-premixed pilot stabilized flames

Rainbow schlieren deflectometry (RSD) integrated with ultra high-speed digital imaging system is used to characterize a turbulent low-density jet through statistical description of path-integrated measurements. Unlike deconvoluted measurements, statistics of deflectometric data are free from approximations and can be utilized as benchmark to compare and validate path-integrated quantities derived from large-eddy and/or direct numerical simulations. Deflectometry techniques allow non-intrusive measurements to probe difficult to access near-field region of the jet exit. The experimental system consists of a helium jet discharged vertically into ambient air from a round tube injector of 4 mm inside diameter (d) and jet exit Reynolds number of 4000. Rainbow schlieren apparatus was configured to cover the near-field axial range of 0 to 20d downstream of injector exit at pixel resolution of 124 μm, temporal resolution of 20 μs, and image acquisition rate of 50,000 frames per second to capture a wide range of turbulent structures. Deflectometric measurements are utilized to estimate integral length scales, integral time scales, and wavenumber spectra at different locations in the flow field. Results show characteristics of a developing turbulent flow in the axial direction with gradual establishment of order. Space-time cross-correlation functions show that the Taylor's hypothesis of frozen flow turbulence is strictly not applicable in the nearfield. Two point cross-correlation functions in transverse direction represent high intensity fluctuations and possible noise source locations.

8th US National Combustion Meeting 2013

Ultra high speed rainbow schlieren deflectometry for statistical description of turbulent low-density jets

We present parallelization of single and two phase flow CFD solvers on a graphics processing unit (GPU) platform. Numerical simulations are done for some standard benchmark test cases for both single and two phase flow solvers. The formulation is based on finite volume method with SMAC algorithm on regular cartesian and collocated grid. Volume of fluid method in used for tracking the interface in multiphase flow solver. Pressure poisson equation is the most time consuming part of the solvers and hence this part is imported on to GPU. Pressure Poisson equation is solved by the conventional Gauss siedel method. Present day modern graphics hardware has several hundred cores which can be effectively used by CFD solvers to parallelize the computation. The results are validated against the reference solutions of the teat cases. A comparison is done between CPU and GPU simulations to estimate the computational acceleration and accuracy obtained. © IEEE 2013.

2013 National Conference on Parallel Computing Technologies, PARCOMPTECH 2013

Single and two phase flow CFD solvers using GPU

Titanium alloys possess low formability and high flows stresses and are difficult to form without using thermal aid to reduce the flow stress. It has been observed that high density electric pulse aide plastic deformation through electron-dislocation interaction and this phenomenon is termed as electro-plasticity where the reduction in flow stress is not due to resistive heating. Present work makes use of high density DC pulses to deform a Ti alloy using incremental sheet metal forming (ISMF) to emphasize the importance of tool configuration to minimize the resistive heating. Results indicate that the tool configuration plays a significant role to reduce the effect of resistive heating and to enhance effectiveness of electro-plastic effect.

Lecture Notes in Engineering and Computer Science

Importance of tool configuration in incremental sheet metal forming of difficult to form materials using electro-plasticity

A wide spectrum of electrokinetic studies is modeled as isothermal ones to expedite analysis even when such conditions may be extremely difficult to realize in practice. Going beyond the isothermal paradigm, we address here the case of flow induced electrohydrodynamics, commonly streaming potential flows, in a situation where finite temperature gradients do exist. By way of analyzing a model problem of flow through a narrow parallel-plate channel, we show that the temperature gradients applied at the channel walls may have a significant effect on the streaming potential, and, consequently, on the flow itself. Our model takes into consideration all the pertinent phenomenological aspects stemming from the imposed thermal gradients, such as the Soret effect, the thermoelectric effect, and the electrothermal effect, by a full-fledged coupling among the electric potential, the ionic species distribution, the fluid velocity and the local fluid temperature fields, without resorting to ad hoc simplifications. We expect this expository study to contribute significantly towards more sophisticated future endeavors in actual development of micro- and nano-devices for applications simultaneously involving thermal management and electrokinetic effects. © 2013 American Physical Society.

Fulltext

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Electrohydrodynamics within the electrical double layer in the presence of finite temperature gradients

A geometrical nonlinear analysis of a symmetric, variable angle tow (VAT), composite plate structure under inplane shear load is investigated in this work. The nonlinear von- Karman governing differential equations (GDEs) based on stress function and displacement function are derived for postbuckling analysis of symmetric VAT plate structures. A numerical methodology based on the differential quadrature method (DQM) is developed for solving the GDEs of VAT plates. The methodology is applied to solve the postbuckling problem of VAT plates with linear fibre angle orientations under simply supported plate boundary conditions. To show the accuracy and robustness of DQM, results are compared with commercial finite element analysis. The postbuckling behaviour of VAT plates under positive and negative shear is studied for different VAT fibre orientations, aspect ratios and their performance is compared with straight fibre composites. In addition, the influence of the direction of shear on the postbuckling behavior of VAT plates under axial compression is studied. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

Postbuckling analysis of variable angle tow composite plates under shear load

A geometrical nonlinear analysis of a symmetric, variable angle tow (VAT), composite plate structure under inplane shear load is investigated in this work. The nonlinear von- Karman governing differential equations (GDEs) based on stress function and displacement function are derived for postbuckling analysis of symmetric VAT plate structures. A nu- merical methodology based on the differential quadrature method (DQM) is developed for solving the GDEs of VAT plates. The methodology is applied to solve the postbuckling problem of VAT plates with linear fibre angle orientations under simply supported plate boundary conditions. To show the accuracy and robustness of DQM, results are compared with commercial finite element analysis. The postbuckling behaviour of VAT plates under positive and negative shear is studied for different VAT fibre orientations, aspect ratios and their performance is compared with straight fibre composites. In addition, the influence of the direction of shear on the postbuckling behavior of VAT plates under axial compression is studied. © 2012 AIAA.

Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

Tool condition monitoring by machine vision approach has been gaining popularity day by day since it is a low cost and flexible method. In this paper, a tool condition monitoring technique by analysing turned surface images has been presented. The aim of this work is to apply an image texture analysis technique on turned surface images for quantitative assessment of cutting tool flank wear, progressively. A novel method by the concept of Voronoi tessellation has been applied in this study to analyse the surface texture of machined surface after the creation of Voronoi diagram. Two texture features, namely, number of polygons with zero cross moment and total void area of Voronoi diagram of machined surface images have been extracted. A correlation study between measured flank wear and extracted texture features has been done for depicting the tool flank wear. It has been found that number of polygons with zero cross moment has better linear relationship with tool flank wear than that of total void area. © 2013 Elsevier B.V. All rights reserved.

Journal of Materials Processing Technology

Progressive cutting tool wear detection from machined surface images using Voronoi tessellation method

The purpose of this paper is to understand the growth and spread of fire through compartment connected to vertical shaft in tall building. The transport phenomena due to fire have been modeled as buoyancy induced turbulent flow in tall building. The governing equations comprise the Reynolds averaged Navier-Stokes (RANS) equations with the K-É" turbulence model in a stream function-vorticity formulation approach. The governing equations are solved by high accuracy compact finite difference schemes with the four stage Runge-Kutta method for time integration. Results are reported for two different Grashof numbers Gr = 1010 and 1011. The effects of vertical passage between compartment and shaft, multiple vertical vents and significance of flow through ceiling vent in tall building are presented. The thermal plume growth rate, the ambient entrainment flow rate and the bidirectional oscillatory nature at the vent openings are reported. A significant change in the flow behavior is observed by varying the size of vertical passage between compartment and shaft. The flow behavior through vertical and ceiling vents is presented. The flow patterns in the shaft show complex flow structure with multi-recirculating convective cells. The present results are matching with the numerical and experimental results available in the literature. © 2013 Elsevier Ltd.