This issue

Future Tense: Geo Thermal Energy in india P.1

Researcher: Nikoas Otto P.2

Instrumental: RTD Sensor P.2

Students' Corner: Cracking Interview P3

Software: Plot Digitizer P3

Industry insight: TATA Consultancy Engineering P4

TAPASTAPASTAPASTAPAS

FROM the Editors' Desk

We hope that the first issue of the Tapas was interesting enough to increase hunger of reading more and more. We have received immense support from all of you and we are thankful to you for that. In past one month activities like Inauguration ceremony of Tapas and thermal sciences student get together has acted like a catalyst to increase the interaction between the students of the department. We hope to have the same momentum throughout the semester. Finally we wish you a happy reading for the second issue of Tapas.

Meaning of TAPASTAPASTAPASTAPAS

Tapas is derived from the sanskrit word tap which means "heat" from fire. In our literature, fusion words based on tapas are widely used to expound several spiritual concepts that develop through heat or inner energy, such as meditation. Friends, it is the fire that burns within us that is needed to achieve the very difficult goal to foster self-control, focus, simplicity, wisdom and integrity. It is our motto to reflect all these qualities in Tapas.

Chief Editor: Dr S Jayaraj

Future Tense -Geo Thermal Energy in India The adjective geothermal originates from the Greek roots geo, meaning earth, and thermos, meaning heat. Geothermal energy is thermal energy generated and stored in the earth. Thermal energy is energy that depends on the temperature of matter. Earth’s geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, from volcanic activity, and from solar energy absorbed at the surface. The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface. Indian Scenario India has reasonable potential for geothermal energy; The geothermal provinces in India can produce an estimated 10,600 MW of power. India is one of the earliest countries to begin geothermal projects way back in the 1970s itself. However, at present there are no operational geothermal plants exist in India. There is also no installed geothermal electricity generating capacity as of now and only direct uses (eg. Heating, Drying etc.) have been detailed. However, Thermax (a capital goods manufacturer based in Pune), has entered an agreement with Icelandic firm Reykjavík Geothermal. Thermax is planning to set up a 3 MW pilot project in Puga Valley, Ladakh (Jammu & Kashmir). Reykjavík Geothermal will assist Thermax in exploration and drilling of the site. India’s Gujarat state is drafting a policy to promote geothermal energy.

Various assessment studies and surveys undertaken so far have resulted in the identification of 340 hot springs across India. The discovery of vast geothermal reservoirs at Puga in the north-west of the Himalayas and Tatapani fields on the Narmada in central India also augurs well for the country. Potential Geothermal regions/sources With India’s total geothermal power potential of 10,600 MW, the following are the region wise split up for geothermal energy availability in India.

Province Surface Temp (°C)

Reservoir Temp (°C)

Himalaya >90 260 Cambay 40-90 150-175 West coast 46-72 102-137 Sonata 60 – 95 105-217 Godavari 50-60 175-215

Article Compiled By: Mayur P. Bonkile

02 I S S U E

F e b r u a r y 2 0 1 5

M TECH-THERMAL SCIENCES, DEPARTMENT OF MECHANICAL ENGINEERING,

NATIONAL INSTITUTE OF TECHNOLOGY,CALICUT

(For internal circulation only)

Bird WatchingBird WatchingBird WatchingBird Watching

Spot this bird named 'Green Bee Eater' (Probable location near central workshop, found

during noon time around 3 pm)

Researcher: Nikolas Otto

Nikolaus Otto, born at Holzhausen, Hesse-Nassau, was the son of a farmer. Otto left school at 16, and later moved to Cologne where he became fascinated by the gas engines developed by Frenchman Jean-Joseph-Étienne Lenoir and displayed for the first time in 1859. Lenoir's engines had a two-stroke design and burned coal (or illuminating) gas; they were also inefficient. Nevertheless, in 1861, Otto built an experimental engine based on Lenoir's design. Three years later, he joined forces with industrialist Eugen Langen and together they formed the Gasmotorenfabric Company with its factory at Deutz near Cologne to build and market his engines. Otto and Langen had the able assistance of Franz Reuleaux, Gottlieb Daimler, and Wilhelm Maybach as part of their engineering team. In 1867, Otto and Langen announced their first production engine. This was a noisy two-stroke engine that improved upon the Lenoir design by compressing the gas before it was ignited. This new Otto engine was a commercial success, and Otto and Langen continued their collaborative achievements by building a radically new engine in 1876 (the four-stroke internal combustion engine), which was immediately dubbed the "Otto Silent." The inefficiency of Lenoir's two-stroke engine was due to the fact that (in addition to not compressing the gas before ignition) the intake of the fuel, its combustion, and the exhaust of the burnt gases had to be accomplished within one back-and-forth motion of the piston. This was to be coupled with a rotary crank to convert the reciprocating motion to rotary motion. Otto's four-stroke engine separated these various tasks. In his engine, the first downward motion of the piston drew an air and gas mixture into the cylinder; on the upward stroke, this mixture was compressed. When the piston was near the top of this motion, the mixture was ignited, driving the piston down and providing power. The fourth stroke, upward again, pushed the exhaust gases out of the cylinder. The intake and exhaust actions were controlled by valves that opened at precisely the right moment by being geared directly to the crank shaft. The Otto four-cycle engine was an enormous success, so successful that the engine is quite often referred to as the "Otto-cycle" engine. The Otto-Langen firm sold over 50,000 of these four-stroke engines in the 17 years following their introduction. Despite Otto's commercial success, he encountered legal problems over his patent of his four-stroke engine when several others challenged his right to the invention. A Munich watchmaker, Christian Reithman, designed and built a four-stroke engine in 1872; Gustav Schmidt of Vienna set out the principles of the Otto-cycle engine in a paper in 1861. And, most notably, Frenchman Alphonse Beau de Rochas described the cycles of intake, compression, power, and exhaust in a theoretical work published in 1862. Although the courts invalidated Otto's patent in 1886 due to the claims of Beau de Rochas and others, the Otto-cycle engine's superiority assured its continued success. It is the Otto-cycle engine that made possible automobiles, motorcycles, powerboats, and aircraft, all of which require a small, light, and efficient engine. Nikolaus Otto died in Cologne on January 26, 1891. Compiled By: Gurpreet Singh

Instrumental : RTD Sensor - Nitish Kumar

What is a RTD??

Resistant Temperature Detectors (RTDs) is a temperature measurement sensor which contains a

resister that change resistance value of the RTD element as temperature changes. Most RTD

elements consist of a length of fine coiled wire wrapped around a ceramic, mica or glass core.

The element is typically relatively fragile, so it is generally installed inside a stainless steel sheath

or protective tube to protect it. The RTD element is constructed from a pure metal, the resistance

of which, at various temperatures, has been documented by various international standards

institutes. This have been used for many years to measure the temperature in many industrial

processes and in laboratories. Compared to thermocouples and thermistors, RTD known for good

accuracy and stability.

Why use an RTD instead of a thermocouple or thermistor sensor?

Each type of thermocouple has a particular set of conditions for which it is best suited, otherwise

error will be more. Hence to use thermocouple in a more efficient manner, we should know the

range of its temperature measurement and chemical resistant of the thermocouple installation

condition/environment. RTDs offer several advantages over thermocouple.

• A wide temperature range

(-50 to 500°C for thin-film and -200 to 850°C for wire-wound)

• Good accuracy with less response time.

• Good interchangeability

• Long-term stability

• It has good linear characteristics over a wide range of temperature

Most suitable use of RTD: Generally RTD has wide range of application in temperature

measurement. But this is more preferred where high accuracy and stability are required. RTDs

also feature high immunity to electrical noise and are, therefore, well suited for applications in

process and industrial automation environment. Especially around motors, generators and other

high voltage equipment where chances of electrical short circuiting is more. I have experienced

using pt-100 RTD to measure the temperature of hot/boiling water where open electrical circuit

is placed in water.

RTD metals: RTD element is constructed from pure metal for good accuracy and stability.

Platinum, Copper and Nickel metals are widely used worldwide. Out of these Platinum is widely

used due to inert nature and negligible effect of oxidation and corrosion (least reactive and

stable). These three metals are having different resistance variations with respect to the

temperature variations, that is called as the resistance-temperature characteristics. Platinum has

the temperature range of 650°C, and then the Copper and Nickel have 120°C and 300°C,

respectively. The figure shows the resistance-temperature characteristics curve of the three

different metals. For Platinum, its resistance changes linearly by approximately 0.4 ohms per

degree Celsius of temperature for the full measurement range.

Resistance-temperature characteristics of metals and RTD Sensor Picture

Pros and cons:

Good stability and linearity, excellent accuracy, contamination resistant, area temperature

sensing, good repeatability

Compared to thermocouple, the cost of RTD is higher. Measurement temperature range of RTD is

low compared to thermocouple. Medium sensitivity at small temperature changes is an

additional disadvantage.

Where to get. ??

Pt-100 RTD sensor Easley available in Coimbatore and Bangalore at many shops. For special type

of RTDs one can give special order according to the requirement.

References Used:

http://www.omega.com/temperature/pdf/rtd_gen_specs_ref.pdf http://ultra-nspi.com/information-central/rtd-termocouple-comparison/ http://electrical4u.com/resistance-temperature-detector-or-rtd-construction-and-working-principle/

Software: Plot Digitizer

When you are making your own research paper in many instances you will need to compare your graph with the existing one. In order to do so Plot Digitizer will help you. This is an open source software.

This program will allow you to take a scanned image of a plot (in GIF, JPEG, or PNG format) and quickly digitize values off the plot just by clicking the mouse on each data point. The numbers can then be saved to a text file and used whenever you need them. Plot Digitizer works with both linear and logarithmic axis scales. Besides digitizing points off of data plots, this program can be used to digitize other types of scanned data (such as scaled drawings or orthographic photos). To make the digitizing task easier, this program includes many handy features. For example: You can recalibrate the Y axis without having to recalibrate the X axis (multiple sets of data are commonly plotted with the same X axis). You can insert points between two already digitized points by right clicking and choosing "Insert" from the pop-up menu. You can delete points by right-clicking on the points and choosing "Delete". You can move points by clicking and dragging them. You can compute the length of a digitized curve and you can compute the area of a digitized polygon. You can zoom images in and out. You can save calibrations for an image for later use, and finally, there is unlimited undo/redo. Source: http://plotdigitizer.sourceforge.net/

Selection Procedure: There were total three rounds of interview namely Technical Round, Managerial Round and HR Round. Some of the questions posed are given here. Technical Round Questions:

• Tell about yourself. • Explain Hoop stress. • What are your areas of interest in Mechanical Engineering? • Tell about your B.Tech. project. • What real time working conditions of power plant have you incorporated in your B.Tech. project? • What is thermal stress? • Tell about your M.Tech. project. • What is significance of adding Nano particles to fuel? • What are you going to prove through your M.Tech. project?

Managerial Round Questions:

• Tell something about yourself? • Why did you opt Mechanical Engineering? • Why did you choose NIT Calicut to do your Masters? • Name the subjects you study in your Masters course. • Did you do any course on CFD? • How well do you know ANSYS? • What programming languages do you know? • Will you be able to write any program that I give now? • Tell me about your M.Tech. Project. • What is Interferometry? How do you employ it in your Project?

HR round Questions:

• Tell about yourself. • What is entropy? • What is the significance of maximum entropy? Which have maximum entropy the living person or

the dead person? • What is Reynolds number? • What are different types of flow? • What is Brownian motion? • Draw Carnot cycle on T-S plane and P-V plane. Explain the various processes in it. • Are you ready to work abroad? Say in Japan. • What are your hobbies? • Are you a spiritual person totally? • If I have to ask you which God do you like the most then what will be your answer? • Name the Dasavataras. • How can you say that Krishna is the supreme Lord when he is an incarnation of Lord Vishnu? • Do you have any Questions?

Students' Corner: Cracking Interview -by Balraju Gayatrhi The student got placed in TATA Consultancy Services (Engineering & Industrial Services)

Shares h er experience of TCS interview panel with Tapas

Industry Insight: TATA Consultancy Services (Engineering & Industrial Services ) TCS Engineering and Industrial Services (TCS EIS) is a business unit of Tata Consultancy Services (TCS), wiz. one of the largest multi-services company of India. According to the total revenue generated by TCS, currently TCS EIS is on sixth place out of eight service lines and generating 4.6% revenue. As it is an emerging sector, many career possibilities are there. The main focus of TCS EIS is to enhance the innovation capacity and enable the launch of differentiating products. TCS EIS product engineering solutions cover multi-disciplinary system engineering, like

• Automotive

• Aerospace

• Energy

• Industrial Machinery

• Consumer Electronics

• Telecom

• Semiconductor

• Pharma

• Life Science

• Utilities

• Retail & many more

TCS EIS mainly helps in the development of a product and also helps to launch the product. Their main focus is on the developing countries. TCS EIS also provides Computational research laboratories which are very useful for High Performance Computing (HPC) applications and cloud services. As TCS EIS dealing with almost every aspect of engineering, they require engineers from every engineering branch. Currently they are dealing with various clients including Nissan Motors, Ferrari, Siemens, IISC, IIT’s, HAL, NAL etc.

Upcoming Conferences National Conference on Emerging Research and Advances in Mechanical Sciences

(ERAMS-2015), Chennai, India

27th March 2015

International Conference on Applications of Engineering, Science and Technology, Madurai, India 13th April 2015

International Conference “Computational and Informational Technologies in

Science, Engineering and Education” (CITech-2015), Almaty, Kazakhstan

24-27 September 2015

23rd National and 1st International ISHMT-ASTFE Heat and Mass Transfer

Conference, Trivandrum, India

17-20 December 2015

Fact File

TAPASTAPASTAPASTAPAS Send your articles and/or suggestions at: thermal@nitc.ac.in

Issue 01 January 2015

Fact File

world’s largest single turbine geothermal

power plant at Kenya can generate

140 Megawatts (MW)

The earth gets 174 Petawatts of incoming solar

radiation at the upper atmosphere. About

30% is reflected back to space and the rest

is absorbed by oceans, clouds and

land masses