Melting and freezing phenomena are inherent to several important cross disciplinary applications such as manufacturing of cast products, welding and other fusion processing, polymer processing, food processing, and geophysical systems. These are typically multi-scale and multi-phase in nature. The final product such as an automobile piston or an ice-cream, is a result of a controlled processing of a multi-component material in liquid or semi-solid state.

The pulverised coal combustion in a swirl burner is a complex phenomenon. A simplified numerical model, using RANS approach, has been developed in order to predict the combustion processes in a swirl burner with an accuracy comparable to that of Large Eddy Simulations (LES). The effect of different combustion environments such as air, oxy-steam (O 2 /H 2 O) and oxy-recycled flue gas (O 2 /CO 2 ) on gas temperature and NO concentration has been studied.

Combustion in a conventional spark ignition engine is initiated by a spark. High temperature zone of initially spherical shape is created by the spark and it grows to consume turbulent premixed fuel-air mixture in the combustion chamber.In direct numerical simulation (DNS) all the length and time scales are resolved. DNS of growth of a flame kernel in a turbulent premixed medium provides fundamental insights into the interaction of flame kernel with turbulence.

A full anechoic chamber has recently been installed in the Aerodynamics Laboratory of the Department of Aerospace Engineering. All four inside walls including ceiling and floor are fitted with sound absorbing non-reflecting wedges which provide ambience with lower cut-off frequency of 200 Hz.

This all steel suction type wind tunnel is housed in the Department of Aerospace Engineering and has many unique features. For example, it has high aspect ratio honeycomb constructed out of thin acrylic sheet and 5 very fine stainless steel screens in the settling chamber followed by a 9 to 1 contraction for excellent quality flow with good uniformity and low turbulence level in the test section measuring 3’ x 3’ in cross section and 8’ in length. With these not so big dimensions this wind tunnel happens to be the largest size wind tunnel in the state of Maharashtra.

Missile based electronic warfare involve a number of techniques, like remote eves dropping, signal jamming and decoy signal generation. For decoy applications, dummy missile has receivers working over a very wide bandwidth that can sense the incoming signals from the enemy missile, and then play it back. The key requirement is that the antenna for such decoy systems must be able to receive and transmit simultaneously, over a very large bandwidth. Secondly the incoming wave can be both left hand circular polarised (LHCP) and right hand circular polarised (RHCP).

Directed energy systems (DES) are a class of systems used for various purposes like Electronic warfare, remote mine clearing and testing the vulnerability of electronic systems under Electromagnetic radiation. They have several advantages over conventional weapon systems like limited debris or garbage production and also they are affected less by rain or fog. For DES, a high power source like virtual cathode oscillator (vircator) or relativistic magnetron is used. These sources have the capability to produce power in the range of Gigawatts.

The science of control engineering involves modeling and ‘control’ of dynamical systems, or in simple words, understanding and manipulating systems that evolve with time. There is a wide gamut of areas that fall under this broad umbrella: economics, biology, environment and engineering to name a few. Our group studies the control of
mechanical systems (mobile robots), aerospace systems (spacecrafts), locomotion of microrobotic mechanisms, and the underlying mathematical framework to model, analyse and synthesise control laws for these systems, ie., differential geometry.

UAS are known under various different names and acronyms, such as ‘Unmanned Aerial Vehicle’ (UAV), ‘aerial robot’ or simply ‘drone’. An UAS typically comprises of an unmanned aircraft (UA), a ground control station (GCS) and a communications data link for the UA command and control from the GCS, host of sensors and a data acquisition device.

■ The robot, which is completely covered, can maneuver in any direction

■ Design is based on pendulum and yoke assembly

■ Entire electronics is within a spherical shell

■The gearless design supports jerky movements so that the application is not limited to a planar environment 

■ Each part inside the shell moves when the robot moves. Major challenges such as placement of electronic and mechanical components for weight balance and non winding of wire during the movement, were addressed

■ Two-pendulum design is developed to avoid gears in the assembly

IIT Bombay Racing is a Formula Student team, with 70 enthusiastic undergraduate members who aim to conceive, design and fabricate an electric race car through innovation to compete in international Formula Student events. The project challenges students to go the extra step in their education by incorporating into it intensive experience in building and manufacturing as well as considering the economic aspects of the automotive industry.We became the first ever Indian team to successfully build Aluminium Honeycomb Composite Chassis.

Textile dyeing in supercritical CO2 fluid offers multiple advantages as it provides an effective replacement of the traditional water based process which typically results in generation of large volumes of effluents and therefore an environmental stress. Additionally, SCFTD allows relatively lesser consumption of energy and solvents. Research carried out at IIT Bombay as well as by other groups internationally has shown that supercritical fluid (SCF) also provides an excellent medium for dye dissolution and fastening to fabrics.

A construction technique using lightweight geomaterials has many practical advantages because of their light self-weight, which makes it possible to reduce large deformations and differential settlement of soft ground or a foundation with poor bearing capacity. Nowadays expanded polystyrene (EPS) blocks are used with soil to make it lightweight material. Few applications like embankment construction, retaining walls and road construction can be mention. These blocks are manufactured by industry in regular shapes only.

A miniature CBR apparatus was fabricated which is very handy and portable, unlike to that of the standard CBR apparatus which is very heavy and consumes lot of time and effort for conducting the test. This apparatus is very useful in improving the soil properties especially with the new innovative nanotechnology based materials as the apparatus would require lesser quantity in mixing with respect to the lesser size of the mould.

The increase in population and the surge in urbanisation in both the developed and the emerging economies are resulting in a decrease of suitable land for development of infrastructure. Consequently, it can be expected that the need to quarry slag heaps and landfills containing such materials for use in construction, such as earthworks, pavements and buildings, will increase rapidly.

Consolidation of soil by surcharge loading with prefabricated vertical drains is an effective ground improvement technique in saturated cohesive soils such as marine clay. Four types of band-shaped drains made from singlelayer woven and non-woven jute geotextile filter fabric wrapped around a core of coir ropes or mats, designated as natural drains, were developed and fabricated. Laboratory marine clay confined discharge capacity and large-scale consolidation tests were conducted on the natural drains and commercially available polymer-based drains.

Contemporary research on gas turbine is focussed on achieving improved performance with lower emissions while avoiding combustion instabilities. Gas turbine industry is focussing mainly on simulations, for cutting down experimental iterations, cost and development time. In our laboratory, gas turbine combustion is simulated using a real life combustor with working variables of an actual gas turbine engine. An experimental facility is also created using one of the ‘can’ combustors of the gas turbine to imitate the actual scenario found in the engine.

It is well known that the traditional paradigm of the materials science tetrahedron depicts the inter-dependent relationship among the structure, properties, processing, and performance of a material. The demand for high performance structural materials for real world applications has undoubtedly driven scientific efforts for the past few decades due to stringent regulations on efficiency and emissions.

Increasing degree of miniatursation of structures and devices has thrown open new observations in a material's response to different loading environments that are starkly different from that of the bulk. Thin films, nanostructures, MEMS and several other systems belong to this category. The 'smaller is stronger' and 'inverse Hall-Petch effect' are typical size effects that occur when the external surface or internal interface shrinks in size. Brittle materials become more damage tolerant while ductile materials tend to become increasingly brittle at small dimensions.

India is infamously called the ‘diabetes capital of the world’. With over 40 million diabetics in the country, we have a distinction of having the highest number of diabetics for any country. This has huge implications on the country’s healthcare, forcing doctors, scientists and citizens to work together to manage and remediate this condition. Now, researchers at the Indian Institute of Technology Bombay (IIT Bombay) have some sweet news for diabetics. They have developed a polymer based bioartificial pancreas that can be implanted inside the body, thus helping in managing diabetes.