Research
My Research Interests
Turbulence
Bluff Body Flow
Jets
Reduced order modeling
Flow control
Electronic cooling
Droplet Dynamics
Current Research
Synthetic Jet
Synthetic jets generate jets with zero mass flux by periodically discharging and sucking fluid out of a cavity having an orifice. A cavity with an oscillating surface known as a membrane or diaphragm and a small orifice opening are typical components of a synthetic jet device. Two strokes, the ejection stroke and the suction stroke, comprise the working principle of a synthetic jet. During the ejection stroke, the fluid in the cavity is expelled into the surrounding environment via the orifice, and the shear layer that has separated from the inner wall of the orifice forms a vortex ring. Due to its self-induced velocity, the vortex ring evolves and moves downstream. In the suction stroke, negative pressure is created in the cavity by the outward moment of the diaphragm, and the surrounding fluid around the orifice is drawn into the cavity. The vortex rings developed in the preceding ejection stokes, which have traveled an ample distance from the orifice, remain uninfluenced by the suction stroke. This periodic motion between the ejection and suction stroke creates a string of coherent vortex rings that propagate downstream to add momentum into the system without adding mass flux. Eventually, these coherent vortex rings roll down, merge, develop instability radially, and finally make the transition to turbulence. In our studies, we explore synthetic jets as a flow control technique. Apart from flow control, we are also exploring it as a heat transfer enhancement technique.
Droplet Dynamics
Droplet dynamics refers to the study of the behavior of small droplets of liquid within a fluid medium. This can include the movement and interaction of droplets with each other and solid surfaces, as well as the physical and chemical processes within the droplets. There are many factors that can influence droplet dynamics, including the size and shape of the droplets, the properties of the liquid and the surrounding medium, and the presence of external forces such as gravity or surface tension. One important application of droplet dynamics is in the field of spray technology, where the characteristics of droplets are carefully controlled to optimize the performance of devices such as nozzles and sprayers. Other applications of droplet dynamics include medicine, where droplets are used to deliver drugs or other substances to specific locations in the body, and in various industrial processes, where droplets are used to mix, coat, or transport materials. Droplet dynamics can be studied using a variety of techniques, including experimental methods and computational simulations. Understanding droplet dynamics is important in a variety of applications, including spray and fog formation, inkjet printing, and atmospheric science.
Past Research
Elevated Jet In Crossflow
Coherent structures associated with an elevated jet in crossflow
Related Publications
Sachidananda Behera and Arun K Saha, 2020 “Evolution of the flow structures in an elevated jet in crossflow”, Physics of Fluids, 32, 015102, DOI:10.1063/1.5129498
Sachidananda Behera, Basheer Ahmad Khan, and Arun K Saha, 2023, "Characterization of the turbulent field behavior of an elevated jet in crossflow investigated using Direct Numerical Simulation", Physics of Fluids, DOI: 10.1063/5.0127618
Cough Jet
Evolution of Cough Jet
Sachidananda Behera, Rajneesh Bhardwaj, and Amit Agrawal, 2021, “Effect of co-flow on fluid dynamics of a cough jet with implications in spread of COVID-19”, Physics of Fluids, DOI: 10.1063/5.0064104
Chandra Shekhar Pant and Sachidananda Behera, 2021, “Effect of humidity on the evolution of COVID-19 droplets distribution in extreme in-homogeneous environment”, Indian Academy of Sciences: Sadhana, 46(4), pp. 187(1-11), DOI:10.1007/s12046-021-01712-2
Wall-mounted Finite Cylinder
Re = 250
Re = 10,000
Sachidananda Behera and Arun K Saha, 2019, “Characteristics of the flow past a wall-mounted finite-length square cylinder at low Reynolds number with varying boundary layer thickness”, ASME. J. Fluids Eng., 141(6), 061204-17, DOI: 10.1115/1.4042751
Sachidananda Behera and Arun K Saha, 2021 “Effect of inlet shear on turbulent flow past a wall-mounted finite-size square cylinder”, Ocean Engineering, 234 (2021) 109270, 1-19, DOI:10.1016/j.oceaneng.2021.109270