Respiratory Disease Transmission

Our group is dedicated to advancing the understanding of respiratory disease transmission through a comprehensive approach incorporating experimental, simulation, and analytical tools. Our primary objective is to gain a comprehensive understanding of the complex and turbulent nature of respiratory disease transmission. Through our research, we aim to contribute to developing evidence-based guidelines for disease prevention and control, ultimately striving for a healthier and safer future for all.

Within our research, we place a strong emphasis on evaluating the mechanisms associated with sneezing, coughing, and normal breathing, as these actions play a critical role in disease transmission. By meticulously examining these behaviors, we aim to uncover essential insights into the spread of respiratory diseases and identify effective strategies to mitigate their transmission. Furthermore, we diligently assess the efficacy of various protective equipment, including face masks and shields, in preventing the transmission of respiratory diseases. Through rigorous experimentation and analysis, we seek to determine the optimal design and usage of such protective measures.

Our research also places special emphasis on the indoor environment. By investigating the dynamics of airflow and ventilation systems, we strive to identify strategies that promote optimum ventilation and minimize the risk of infection in indoor spaces.


Active Flow Control Devices

Many engineering applications like aerodynamics, electronics cooling, process industries and combustion require effective fluid utilization. Such applications demand an active flow control technique to manipulate the flow field to achieve the desired effects like turbulence enhancement and vortices. Existing flow control devices have limited scope due to their ineffectiveness in manipulating the flow field to achieve these desired effects.

We proposed and demonstrated a Coaxial Synthetic Jet (CSJ) system for flow control application. By employing two piezo-electric diaphragms arranged coaxially with a 0° orientation angle, the system generates and controls flow jets to achieve the desired effect. These diaphragms can be independently operated at different amplitudes and frequencies without affecting the flow in either cavity. Moreover, the CSJ allows for adjusting phase differences between the diaphragms, ranging from 0° to 180°, providing versatile modulation capabilities. The compact design of the CSJ enables easy integration into electronic components, aerodynamics flow control, mixing, and combustion applications. With its ability to achieve different mass flux ratios, the CSJ represents a significant advancement in flow control technology.

In another invention, we introduced an innovative focusing technique to enhance the strength of synthetic jets (SJs) in the far-field. SJs often suffer from reduced vortex coherence, limiting their wide applicability. This issue also affects Synthetic Jet Arrays (SJ arrays) composed of multiple adjacent actuators, where destructive interactions between opposite rotating vortices decrease coherence in the far field. The inventors propose focusing as a method to mitigate these destructive interactions in the near field, allowing vortices to evolve effectively, which results in achieving 50% enhancement in jet strength in the far field. Subsequently, constructive merging between vortices amplifies the jet strength in the far field. This novel focusing of SJs holds tremendous potential for enhancing electronic cooling, aerodynamics, and other applications.


Thermal Management

Thermal management is a critical aspect in various engineering applications, including electronics, automotive systems, industrial processes, and more. Efficient heat dissipation is essential to ensure optimal performance, reliability, and longevity of components. Flow control devices play a pivotal role in thermal management systems, regulating the flow of coolant or air to control temperatures effectively.

We are developing novel flow control devices for thermal management, these include, Co-axial synthetic jets, synthetic jet array for steering & focusing, and flexible flaps. These devices can be tailored to make them suitable for near-field and far-field cooling applications, along with spot cooling features.


Bio Inspired Propulsion

Bio-inspired propulsion is an innovative field that takes inspiration from nature's incredible diversity to design propulsion mechanisms for various applications. By emulating the exceptional locomotion abilities of animals and microorganisms, we aim to engineer more efficient, agile, and sustainable propulsion systems.

Our group is trying to understand the propulsive performance of multiple pitching foils. Our study highlighted that side-by-side arrangement of foils in still medium results in the formation of a deflected jet. The extent of jet deflection depends on the phase difference between the airfoils' oscillations and the frequency of oscillation. At lower frequencies of oscillation for a given phase difference, the deflection angle is higher. We observed that the initially deflected jet undergoes a switching process towards the centerline position after specific periods of pitching. This occurs when the vortices from the lower airfoil completely interact with the upper airfoil. Overall, trust can be significantly enhanced by maintaining an optimum phase difference between the pitching foils.

The addition of an auxiliary small foil can significantly enhance the propulsive performance of the main foil. Based on vorticity dynamics, three main flow regimes are identified, depending on the vortex structures shed by the airfoils. The auxiliary airfoil's presence significantly alters the main airfoil's hydrodynamic characteristics, leading to considerable enhancements in thrust (up to 23%) and efficiency (up to 49.2%) compared to an isolated airfoil.

These results provide valuable insights into the pitching of side-by-side airfoils and the formation of deflected jets. Understanding these phenomena can have implications for engineering applications, particularly in the domain of bio-inspired propulsion systems.


Opto-Mechanical Sensors for Industrial Application

Harsh environments and high temperatures are the major factors responsible for the failure of sensors used in industrial applications, especially in process monitoring. We are engaged in the development of next-generation measurement devices for industrial applications. These sensing devices are mainly based on Photonic Crystal fibre-based interferometers. High sensitivity, immunity to electromagnetic interference, and flexibility in design are some of the key features which make Photonic Crystal fibre-based systems suitable for a wide range of parameter sensing. Our group is currently working on developing sensors for flow rate, pressure, and temperature measurement for industrial applications ranging from large conduit pipes to micro channel flows.