Dr. Raghvendra Gupta
Associate Professor
Key Research Areas :Multiphase flow, Microfluidics and micro process engineering, Computational and experimental fluid dynamics.
- Phone No: +91 361 258 3530
- Email: guptar@iitg.ac.in
- Room No: 113
Research
Mutiphase Microfluidics
Slug or Taylor flow and annular flow are the two most common operating regimes that occur in gas-liquid and liquid-liquid flow in mini and microchannels. We have investigated extensively flow and heat transfer in the slug flow regime in straight capillaries using volume of fluid method. Some of this work is highly cited and has been used as a benchmark for validation.
- Gupta, R, Fletcher, DF and Haynes, BS. On the CFD modeling of Taylor flow in microchannels. Chemical Engineering Science, 2009, 64, 2941-2950.
- Gupta, R, Fletcher, DF and Haynes, BS. CFD modelling of heat transfer in the Taylor flow regime. Chemical Engineering Science, 2010, 65, 2094-2107.
- Asadolahi, AN, Gupta, R, Fletcher, DF and Haynes, BS. CFD Approaches for the simulation of hydrodynamics and heat transfer in Taylor flow. Chemical Engineering Science, 2011, 66, 5574-5584.
- Leung, SSY, Gupta, R, Fletcher, DF and Haynes, BS. Effect of flow characteristics on Taylor flow heat transfer, Industrial and Engineering Chemistry Research, 2012, 51, 2010-2020.Leung, SSY, Gupta, R, Fletcher, DF and Haynes, BS. Gravitational effect on Taylor flow in horizontal microchannels, Chemical Engineering Science, 2012, 69, 553-564.
- Asadolahi, AN, Leung, SSY, Gupta, R, Fletcher, DF and Haynes, BS. Validation of a CFD model of Taylor flow hydrodynamics and heat transfer. Chemical Engineering Science, 2012, 69, 541-552.
In most of the process engineering applications, the channels are not straight and have bends and bifurcations. We have studied experimentally gas-liquid flow in a curved channel of 1 mm diameter and observed that the liquid film surrounding the gas core in annular flow is thicker on the inner wall than that on the outer wall whereas the contrary is true for the liquid film surrounding the gas bubble.
- Mishra, DK, Mohanty, D, Gupta, R, Singh, A, Effect of Bend on Film Thickness in Slug, Slug-Annular, and Annular Flow Regimes in Gas-Liquid Flow in Microchannel, Industrial and Engineering Chemistry Research, 2022, 61 (37), 14081-14092.
Janus particles having partly hydrophilic and partly hydrophobic surfaces are used in a number of microfluidic applications. We modelled the flow around a Janus sphere fixed in a channel to understand the effect of Reynolds number, particle to channel size ratio and transverse location of the particle in the channel.
- Dhiman, M, Gupta, R and Anki Reddy, K, Hydrodynamic Interactions between two side-by-side Janus spheres, European Journal of Mechanics-B/Fluids, 2021, 87, 61-74.
- Dhiman, M, Gupta, R and Anki Reddy, K, Drag on Janus Sphere in a Channel: Effect of Particle Position, Journal of Fluids Engineering, 2021, 143 (3).
- Dhiman, M, Gupta, R and Anki Reddy, K, Theoretical and Computational Fluid Dynamics, Lift on Stick and Janus spheres in a channel, 2021, 35 (5), 659-682.
- Dhiman, M, Kumar, S, Anki Reddy, K and Gupta, R, Origin of the long-ranged attraction or repulsion between intruders in a confined granular media, Journal of Fluid Mechanics, 2020, 886, A23.
Biomedical Flows
The work on cardiovascular flows is aimed at understanding flow behaviour at bifurcations which are prone to plaque deposition leading to atherosclerosis. We studied computationally flow in an idealised carotid artery bifurcation to understand the effect of bifurcation angle, size and location of carotid sinus and pulse rate on the hemodynamics and shear stress on the wall which is a critical factor in atherogenesis.
- Nagargoje, M, Mishra, DK and Gupta, R, Pulsatile flow dynamics in symmetric and asymmetric bifurcating vessels, Physics of Fluids, 2021, 33, 071904.
- Nagargoje, M and Gupta, R, Effect of asymmetry on the flow behavior in an idealized arterial bifurcation, Computer Methods in Biomechanics and Biomedical Engineering, 2020, 23, 232-247.
- Nagargoje, M and Gupta, R, Effect of sinus size and position on hemodynamics during pulsatile flow in a carotid artery bifurcation, Computer Methods and Programs in Biomedicine, 2020, 192, 105440.
Recently, we have collaborated with the team of cardiologists and radiologists from VMMC- Safdarjung, New Delhi and NEIGRIHMS, Shillong to analyse the flow behaviour in patient-specific geometries. Using the medical images provided by the medical practitioners, three-dimensional geometrical models of the vessels are created and the flow behaviour is studied.
Multiphase Reactors
The research on multiphase reactors is focused on investigation of local hydrodynamics in lab scale and pilot scale stirred tank reactor and pulsed plate columns using radiotracer-based techniques in collaboration with Prof Rajesh K Upadhyay from IIT-BHU and scientists at BARC. Pulsed plate columns are typically employed for liquid-liquid extraction in the nuclear industry. We have studied local velocity field between two consecutive plates using two different internal plates, sieve plates and slotted plate for single as well as two-phase flow conditions for a range of operating conditions using radioactive particle tracking.
- Pillajetti, P, Gupta, R, Goswami, S, Pant, HJ, Sen, N, Singh, KK, Shenoy, KT, Upadhyay, RK, Investigation of Velocity Field Inside a Single-Phase Pulsed Sieve Plate Column Using Radioactive Particle Tracking, Industrial & Engineering Chemistry Research, 2022, 61, 15423-15432.
The work on stirred tank reactor is focused on gas-liquid flow using dual impeller and the effect of different impeller combinations and distance between them on the gas distribution and liquid velocity field is studied using gamma ray densitometry and radioactive particle tracking.
