Pinch Analysis was originally developed as a thermodynamic tool to conserve thermal energy in chemical process industries through a network of heat exchangers.

Due to the simple design, better atomisation and mixing characteristics, the impinging jet configuration has been a preferred injection system for storable liquid propellant rocket engines. The major problem associated with liquid propellant rocket engines using the impinging jet injector configuration is combustion instability. Acoustic oscillations in the combustion chamber affects the process atomisation leading to oscillatory sheet breakup and spray formation. This further causes unsteady heat release favorable for sustaining the combustion instability.

As we know, energy can’t be converted 100% into work. For instance, about more than a third of energy from fuel in internal combustion engine in a car goes into running the vehicle and majority of the fuel gets wasted as a heat. One can harness part of this waste heat (generated in vehicles, electronic circuits, factories as well as in natural heat sources) and turn it into useful energy, which can partly solve some of our energy problems. Thermoelectric materials converts part of the heat into useful electrical current.

Grain-oriented (GO) materials are commonly used in magnetic circuits of power transformers. They provide a high permeable path for the main magnetic flux with minimum iron (or core) losses for magnetisation along their rolling direction (RD). These materials exhibit hysteretic, anisotropic, and dynamic features in their magnetisation process. Numerical simulations have to be carried out to optimise design, to pre-estimate the losses, and to test design performance under transient conditions.

Vacuum circuit breakers (VCBs) are finding increased usage in the medium voltage range (1 - 52 kV) due to their robustness and compactness. As the entire current interruption process takes place inside a closed vacuum enclosure (vacuum bottle), the VCB is maintenance free. Vacuum technology has progressed over the years and VCBs have become increasingly compact. As a result they have developed an edge over SF6 circuit breakers. Presently, VCBs have a comparable market share as that of SF6 breakers in the switchgear sector.

With the rising demand of the energy, India is looking forward to implement advance technology named fracking to explore previously untapped shale gas resources and to rejuvenate old brown fields. In fracking, a large volume of water is forcefully injected in the subsurface to create fractures. These fractures facilitate the movement of hydrocarbons to the producing well. But one of the first and very crucial stages of fracking is the fracture-mechanical characterisation of the target rocks.

The global energy scenario is in dire need of an overhaul. The goal of meeting the future energy demands is only possible by modernising the exploration and exploitation techniques of the hydrocarbon reserves. India has an extensive reserve of coal which can serve its needs for over a century. The use of novel techniques can maximise the energy recovery from coal, and help in bridging the gap between resource and reserve. One such novel technique is underground coal gasification (UCG), which involves the conversion of coal into fuel gas (syngas) within the earth.

Understanding the flow behavior through fractures is critically important in a wide variety of applications. In many situations, the fluid flow can be highly irregular and non-linear in nature. The study of fluid flow through fractures is helpful for systems involving various aspects of reservoir geomechanics. Fluid flow modeling has a major application in oil, gas production, dam foundation, coal mining and waste disposal, subsurface flow and carbon dioxide geosequestration, natural hazards and shale gas extraction.

Two issues that significantly impact the health of the people in the rural areas are the use of solid fuel for cooking and the use of kerosene for lighting. In addition to the adverse health impacts because of the large quantity of emissions (refer figures), the practice of using solid fuel for cooking also involves a huge amount of drudgery in order to collect the fuel wood. This could be as much as walking about 3 - 5 km/day and mostly involves women.

Half-Heusler thermoelectric materials (crystal structure shown in the figure) have attracted extensive research interest over the last two decades owing to their thermal stability, mechanical strength, and moderate efficiency. This project involves a first principles theoretical evaluation of the electrical and thermal transport properties of three bismuth-based most promising thermoelectric alloys. These are brand new compounds, which are recently proposed to be stable [Nature Chem.7, 308 (2015)] and speculated to have interesting properties.

Hybrid perovskites, CH 3 NH 3 PbI 3 (crystal structure shown on the left figure), is one of the most promising novel materials for solar harvesting. Toxicity of lead (Pb), however, has always remained a concern. In this project, we investigated the electronic structure of complete replacement of Pb by alkaline earth elements (Ca, Sr, Ba) and found them to be wide band gap (E g ) semiconductors (band gap ~ 3.7-4 eV), and hence not suitable as absorber material. This opens up a new avenue to explore these materials as transparent conductor (TC).

Ceiling fan is one of the most widely used home appliances. Unfortunately, it is also one of the most inefficient. The conventional single phase induction motor based ceiling fan consumes up to 70-75 W power while the output is only 20-25 W. Therefore, in order to improve the efficiency, a novel switched reluctance motor (SRM) drive is developed to replace the inefficient induction motor. This drive reduces the power consumption of the ceiling fan by 50%. The developed SRM and its power electronic drive shown in the following figures consume only 34 W at the rated ceiling fan speed.

A novel ferrite based semi-modular dual-stack (SMDS) spoke-type BLDC motor is designed and fabricated for a photovoltaic (PV) powered submersible water pump. A new rotor is designed with minimum flux leakage and without the use of a separate non-magnetic hub for the rotor. The proposed flux barrier arrangement uses the bottom bridge of the conventional spoke rotor, and despite being magnetic reduces flux leakage. The use of ferrite magnets makes the motor more economical compared to the rare-earth magnet based motors.

Depleting fossil fuels and dangerous changes in environment makes renewable energy very attractive. Due to intermittent nature of the renewable energy resources (RES), energy storage systems (ESS) has to be used in conjunction with RESs. Most of these RESs and ESSs are more compatible with DC system and AC. Further, most of the modern electric loads like variable speed drive, LEDs, etc. are more efficient when it is connected to DC supply. So the DC system is dominating by its advantages over AC system in the modern era.

Three phase modular multilevel converter (MMC) shown below is a laboratory model of a system used at the transmitting and receiving end of high voltage DC transmission (HVDC) system. It is capable of converting three phase AC power to DC power or vice versa. The photograph shows the power circuit in three racks for phases A, B and C. Each phase consists of two arms made of a power stack, an arm inductance, voltage and current sensing circuit and power supplies.

This project deals with supercapacitors, which are high-energy capacitors with much higher capacitance than a conventional capacitance of the same size. They are useful alternatives to conventional battery storage systems with higher power density and larger cycle lives. The objectives of the project are: Design and fabrication of power packs by stacking a large no. of supercapacitors: Although supercapacitors have a higher capacitance, the voltage ratings of the devices are considerably low (2.5 - 2.7 V).

Microgrid is a power pool in which a number of generating sources, storage devices and loads are interconnected with each other to exchange power. A load survey was carried out in the IIT Bombay campus to determine the load profile of the campus school, a residential building, an elevator system and the hospital. The objective of the project is to design an AC-DC hybrid microgrid to meet various load profiles, taking the Institutes's campus as an example.

Energy efficient devices contribute significantly towards a greener environment and help tackle climate change. In 2006, the Government of India initiated the program of ‘star labels’ on appliances that provide information regarding their energy efficiency. Initially voluntary and covering few appliances, star label is now mandatory in India for few appliances like the room air conditioners and frost-free refrigerators. While regulations and innovation are crucial to design such devices, consumer choice also plays a significant role.

Power generation using landfill leachate can prevent pollution and serve as alternate source of electricity, say researchers

Study takes us a step closer to harvesting electricity from heat dissipated from electronic devices