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August 03, 2019

Eureka! The Archimedes PrincipleArchimedes was possibly the world's greatest scientist — at least the greatest in the classical age. He was a physicist, mathematician, astronomer, inventor and engineer. Many of his inventions, theories and concepts are still in use today. Perhaps his best-known achievement was his "Eureka" moment, when he discovered the principle of buoyancy.


'Eureka! Eureka!'
Archimedes has gone down in history as the guy who ran naked through the streets of Syracuse shouting "Eureka!" — or "I have it!" in Greek. The story behind that event was that Archimedes was charged with proving that a new crown made for Hieron, the king of Syracuse, was not pure gold as the goldsmith had claimed. The story was first written down in the first century B.C. by Vitruvius, a Roman architect.

Archimedes thought long and hard but could not find a method for proving that the crown was not solid gold. Soon after, he filled a bathtub and noticed that water spilled over the edge as he got in and he realized that the water displaced by his body was equal to the weight of his body. Knowing that gold was heavier than other metals the crown maker could have substituted in, Archimedes had his method to determine that the crown was not pure gold. Forgetting that he was undressed, he went running naked down the streets from his home to the king shouting "Eureka!"


The Archimedes principle
According to Boundless, the Archimedes principle states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid that is displaced by that object.

If a glass is filled to the top with water and then ice cubes are added to it, what happens? Just like the water spilled over the edge when Archimedes entered his bathtub, the water in the glass will spill over when ice cubes are added to it. If the water that spilled out were weighed (weight is a downward force), it would equal the upward (buoyant) force on the object. From the buoyant force, the volume or average density of the object can be determined.

Archimedes was able to determine that the crown was not pure gold due to the volume of the displaced water, because even though the weight of the crown was identical to the weight of the gold that the king gave the crown maker, the volume was different due the various densities of the metals.
Uses of the Archimedes principle

The Archimedes principle is a very useful and versatile tool. It can be useful in measuring the volume of irregular objects, such as gold crowns, as well as explaining the behaviors of any object placed in any fluid. Archimedes' principle describes how ships float, submarines dive, hot air balloons fly, and many others examples, according to Science Clarified. The Archimedes principle is also used in a large variety of scientific research subjects including medical, engineering, entomology, engineering, and geology.
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August 02, 2019

Only one example of the Bugatti La Voiture Noire has been produced and carries a price tag of $12.5 million or Rs. 87 crore, making it the most expensive new car to be sold ever.


What do you do when your garage is full of supercars, hypercars, limited edition cars, yachts, jets or an airline perhaps? You get something that's built just for you and is the only of its kind in the world. Somewhere out there, a certain billionaire has just done exactly that and paid some outlandish amounts of money for the same. We are talking about the Bugatti La Voiture Noire, a car that makes the Chiron look "affordable" with only one to be ever produced. And with a price tag of $12.5 million or ₹ 87 crore (ex-showroom), it is the world's most expensive new car to be sold ever. In fact, the one-off car actually costs about ₹ 132 crore on-road (after taxes).


The Bugatti La Voiture Noire has been commissioned to commemorate the brand's 110th anniversary and made its debut at the ongoing 2019 Geneva Motor Show. Only one example of the all-black car will be produced and has already been sold. The La Voiture Noire pays homage to the Bugatti Type 57SC Atlantic, which was designed by Jean Bugatti, eldest son of founder Ettore. The 57 Atlantic had an iconic all-black variant, which went missing during the Second World War and the new La Voiture Noire takes after it with its all-black paintwork. Globally, there are four examples of the 57 Atlantic available today.


Every component of the Bugatti La Voiture Noire has been handcrafted and the complete carbon fibre body has a deep gloss black finish. The material has been handled perfectly, says Bugatti designer Etienne Salome, adding that the design was worked upon until nothing could be improved. Visually, the Bugatti La Voiture Noire looks almost evil, much like Darth Vader, but equally intriguing. The rear almost floats over the exhausts with the ultra-wide taillights extending from side-to-side.


For what is a bespoke car completely, the La Voiture Noire shares its performance components with the Chiron. The 8-litre 16-cylinder engine develops 1479 bhp and 1600 Nm of peak torque. There are six exhaust pipes at the rear, a reference to the Atlantic's five exhausts. It's also the pinnacle of performance for the internal combustion engine that graces the expo floor that is also celebrating the birth of electric hypercars.














The unnamed owner of the most expensive Bugatti ever will be receiving the finished example almost two and a half years later, during which Bugatti will be working not only on building the car but also on homologating it as well to make it road legal. The La Voiture Noire then, is as rare as they get, nothing short of a piece of art. This one though will be functional.
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August 02, 2019
If you have wondered how reverse parking sensors work, you are not alone. These little technological marvels allow you to back your vehicle out of a driveway or parking space with more confidence and make driving in reverse safer in general. They detect objects in your vehicle's path and emit a sound or beep that lets you know you need to stop and check behind you before proceeding. And, like most technology, it is much easier to add a sensor to your car or troubleshoot and repair one if you know what you're getting into.



How They Work

Parking sensors are labelled by various vehicle manufacturers under many different brand names, such as Park Distance Control, Park Assist, Parktronic, or EPS, but they only come in two varieties: ultrasonic and electromagnetic.


Ultrasonic Sensors
These types emit radio or ultrasonic waves that bounce off of objects behind the vehicle, much like some animals use echolocation. The returning waves are then registered and analyzed by a computer inside your vehicle. By measuring the time it took the wave to return to the sensor as well as any changes in the length or spectrum of the wave, the computer can determine the size and relative proximity of the object behind you. If the wave returns quickly, then the computer knows that something is close behind the vehicle and emits an alarm signal. Most computers and sensors are actually set up to not register signals that indicate an object is more than a certain distance away (usually five to 15 meters depending on the way the system is set up).
Since this system relies on the use of sound waves, there are cases when the sensor cannot properly detect objects behind you. For example, some surface types can interfere with how sound waves reflect, or, if an object is too narrow or small to reflect sound waves, your sensor will not see it. Also, since an ultrasonic system works by using four to six individual sensors mounted on the outside of the car's bumper, there are cases in which blind spots and excess dirt and grimeon the sensors themselves will contribute to a lack of detection.

Electromagnetic Sensors
As indicated by the name, these sensors operate using electromagnetic waves. A transceiver strip generates an elliptical near field behind the car, and hen objects that meet a certain mass requirement disturb that field, a detector picks up the voltage change and sends the information to a computer in the car. The computer analyzes the data to determine the distance to the object and then alerts the driver with a series of tones that grow progressively louder or faster as their vehicle gets closer to whatever is behind it.
Most, if not all, of these sensors mount on the inside of your vehicle's bumper, so there is no issue with dirt interfering with the system's detection capability. These are also the more discreet design; however, they may prove to be a more complicated install for some DIYers.

Detecting Moving Objects

Some parking sensors can detect moving objects as well, but they will react in much the same fashion regardless. In the case of an ultrasonic system, once a sensor receives a signal or wave that the computer determines is close, all sensors on the rear of the vehicle will then send a signal or wave simultaneously. Depending on which sensor receives the returned wave, the computer can determine if the object is moving or not. However, the system will still sound the alarm the entire time the object is within the sensory area.
Electromagnetic sensors will also register a moving obstruction in the same manner as a non-moving one if it's close enough. These sensors actually only react to objects approaching the bumper, so fixed accessories like tow bars don't perpetually set off the alarm, so a moving object, like a person, will set off the alarm until it leaves the field if it is in close enough proximity.
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August 02, 2019
Machine designer is the one who designs the machine and its various elements. A good machine designer possesses some skills that help him/her design the machine elements and machine that meet all the needs of the designer and that helps develop the high quality machine at lowest possible costs.Here are some important skills that a good machine designer should possess.
●      Inventiveness: This skill is the foundation stone for a good machine design engineer. Any new design starts with the need or some objective. A good designer should have inventiveness, which is the ability to think of or discover valuable and useful ideas or concepts for the things or processes to achieve the given objective. Without inventiveness the designer cannot start the process of machine design.
●      Engineering analysis: Engineering analysis is the ability of the designer to analyze the given component, system or the process using engineering and scientific principles. The designer who possesses this skill will be able to find answer to the engineering related problems very quickly for he or she knows what exactly the problem is and where it is.
●      Engineering science: This is another skill without which the designer will just not be able to do any designing. A good designer is the one who has thorough knowledge of and in depth training in the engineering science in which they are doing designing. For instance, if the person doesn’t know what the refrigerator is and other basics of mechanical engineering how will they be able to design the refrigerator?
●      Interdisciplinary ability: A good design engineer is the one who has the ability to solve the problems not only those related to his/her specialty, but also have the ability to competently and confidently deal the basic problems or ideas from other disciplines which are in some or the other manner linked to the machine they are designing.
●      Mathematical skills: All types of designs involve lots of mathematical calculations and iterations. A good designer should have the knowledge of all the basics and advanced mathematical concepts so that they can be applied fruitfully and effectively wherever required.
●      Decision making: During designing many times a number of uncertain situations arrive, in such cases the designer should be able to take the decision with balanced mind considering all the relevant factors involved. If the person doesn’t maintain the balance of mind and doesn’t consider all the relevant factors there are greater chances of taking the wrong decision.
●      Manufacturing processes: The design engineer should have the knowledge of the manufacturing process like cutting, drilling, milling etc and the knowledge of all the machines. They should also the knowledge of potential and limitations of all the machines and manufacturing processes which may be old or new.
●      Communication skills: Communication skill is the ability of the design engineer to express oneself clearly and persuasively orally, graphically as well as in writing.
●     These are the important skills that the machine design engineer or rather any designer should posses. Apart from this there are many other skills desired from a good designers, these are: skill in design, good judgment, simulation skill, measurement skill, thought skill, work in team, ability to make conclusion etc.
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August 01, 2019



Electric cars are already a mainstay on Britain's roads, with a growing number of all-electric models being available to buy right now. The electric effect is now in full force, with established brands committing to offering a wider range of pure electric cars in the future, while those who depend heavily on diesel are seeing sales falter.


Prices are falling, models are diversifying and it's all going hand-in-hand with increased investment and roll-out of charging networks.


But what electric cars are coming? Let take a closer look at what you can expect to see hitting the roads in the next few years.

Lotus Evija










The Lotus Type 130 or Evija as it is called, is an all-electric hypercar limited to just 130 models, but paving the way for future production cars from Lotus. It has been designed for maximum performance, with 2000PS and a 70kWh battery that aims to give 250 miles of range. However, the car will offer blistering acceleration, and while Lotus hasn't given final figures, it'll hit 186mph in under 9 seconds. This car will cost £2 million pounds and preorders are open, asking for a £250,000 deposit.

Ford Mustang electric













Ford announced at the Detroit Motor Show 2018 that it will invest $11 billion in electric vehicles, and plans to have 40 electrified vehicles on the road by 2022, 16 of which will be fully electric, while the rest will be plug-in hybrids. There has been a lot of talk Ford using VW's electric platform which will help kickstart a move into EVs.


There's a new team - Ford Team Edison - looking at the electric future and an "electric Mustang-inspired utility" is one of the vehicles in development. Ford went as far as teasing the Mustang during the launch of the Tesla Model Y and through a neat leak to CNBC, we're slowly learning details.

Lightyear One











The Lightyear One is a luxury saloon that adds solar panels to the roof and bonnet of the car, aiming to give the owner a boost from the sun all the time - even when driving. While much of the car is conventional for an EV, the additional solar panels will give a 12km range boost per hour (in good light). That might mean free charging while parked at the beach - although in winter you'll have to charge it more. However, the asking price for the limited-run Lightyear One will be €119,000, so going solar comes at a price.

Peugeot e-208











Peugeot's hot-selling city car was a big star of the Geneva 2019 show. Riffing off the style of the '80s 205 that's beloved of motoring journalists, Peugeot's put the cat amongst the pigeons by offering a 50kWh electric battery version, from launch.

Tesla Model Y











We all know that Tesla wanted to launch another car and the Model Y slips into the space between the Model 3 and the Model X, a compact SUV. The interior leans towards the Model 3, while the range offers 242 miles with a 0-60mph time of 5.9 seconds, on the most affordable model. It will seat seven, come with long-range and performance versions and be hitting the road in 2020.

Audi Q4 Concept











The Q4 e-tron does two things. It previews a more "sporty", coupe body style version of the Q3 SUV (in the same way a Q8 relates to a Q7) and shows Audi's big push towards fully electric cars. It was previewed at Geneva 2019 but looks very much like the final thing. Expect a production version to follow, soon.

Seat El-Born











Seat is joining the electric car movement with the E-Born, named after a region of Barcelona. The car sits on VW's MEB platform and is due to arrive in 2020, getting its first appearance at the Geneva International Motorshow in 2019 as a concept. Seat is looking at a 420km range (260 miles), with a 0-62kpm time of 7.5 seconds. There will be 204PS from the 150kW motor and a 62kWh battery. 

Polestar 2














Polestar - formerly the performance arm of Volvo - was spun out by owners Geely and has announced its second car, the Polestar 2. This five-door fastback EV will be offering 500km (310 miles) from an 87kWh battery, with 408bph and all-wheel drive, while showing many hallmarks of Scandinavian design. It's also the first car to launch running Android natively, with a huge 11-inch tablet in the centre to control your navigation from Google Maps and your entertainment.

Reservations are currently open for the car which has a guide starting price of €39,900, although the launch edition (with lots of spec additions) will be available for €59,900. There's no confirmation of UK pricing, but it's going to widely available across Europe and in the US.



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August 01, 2019

A tiny satellite under construction at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) could open new horizons in space exploration. Princeton University students are building the device, a cubic satellite or “CubeSat,” as a testbed for a miniaturized rocket thruster with unique capabilities being developed at PPPL.

A group of researchers: Princeton graduate and undergraduate students gather with advisors around model of the CubeSat chassis. From left: Jacob Simmonds, Jerry Xiang, Nirbhav Chopra, Daniel Marlow, Yevgeny Raitses, Seth Freeman, Matthew Bledsoe and Daniel Piatek (Seton Hall student). Photo by Elle Starkman, Princeton Plasma Physics Laboratory
The CubeSat’s thruster, whose development is led by PPPL physicist Yevgeny Raitses, holds the promise of increased flexibility for the tiny satellites, more than a thousand of which have been launched by universities, research centers and commercial interests around the world. The proposed propulsion device — powered by plasma — could raise and lower the orbits of CubeSats circling the Earth, a capability not broadly available to small spacecraft today, and would hold the potential for exploration of deep space.

“Essentially, we will be able to use these miniature thrusters for many missions,” Raitses said.

A fleet of CubeSats
One example: A fleet made up of hundreds of such micropowered CubeSats could capture in fine detail the reconnection process in the magnetosphere, the magnetic field that surrounds the Earth, said physicist Masaaki Yamada. Yamada is the principal investigator of the PPPL Magnetic Reconnection Experiment, which studies magnetic reconnection — the separation and explosive snapping together of magnetic field lines in plasma that triggers auroras, solar flares and geomagnetic storms that can disrupt cell phone service and power grids on Earth.

Key advantage
The miniaturized engine scales down a cylindrical thruster with a high volume-to-surface geometry developed at the PPPL Hall Thruster Experiment, which Raitses leads and launched with PPPL physicist Nat Fisch in 1999. The experiment investigates the use of plasma — the state of matter composed of free-floating electrons and atomic nuclei, or ions — for space propulsion.
A key advantage of the miniaturized cylindrical Hall thruster will be its ability to produce a higher density of rocket thrust than existing plasma thrusters used for most CubeSats now orbiting Earth. The miniaturized thruster can achieve both increased density and a high specific impulse — the technical term for how efficiently a rocket burns fuel — that will be many times greater than that produced by chemical rockets and cold-gas thrusters typically used on small satellites.
High specific-impulse thrusters use much less fuel and can lengthen satellite missions, making them more cost-effective. Equally important is the fact that a high specific impulse can produce a large enough increase in a satellite’s momentum to enable the spacecraft to change orbits — a feature not available on currently orbiting CubeSats. Finally, high thrust density will enable satellites to accomplish complex fuel-optimized orbits in a reasonable time.
These capabilities provide many benefits. For example, a CubeSat might descend to lower orbit to track hurricanes or monitor shoreline changes and return to a higher orbit where the drag force on a satellite is weaker, requiring less fuel for propulsion.
The foot-long CubeSat, which Princeton has dubbed a “TigerSat,” consists of three 4-inch aluminum cubes stacked vertically together. Sensors, batteries, radio equipment and other instruments will fill the CubeSat, with a miniaturized thruster roughly equal in diameter to two U.S. quarters housed at either end. A thruster will fire to change orbits when the satellite passes the Earth’s equator.

Mechanical and aerospace engineering students
Building the CubeSat are some 10 Princeton graduate and undergraduate students in the Department of Mechanical and Aerospace Engineering, with Daniel Marlow, the Evans Crawford 1911 Professor of Physics, serving as faculty advisor. Undergraduates include Andrew Redd (Class of 2020), who leads design and construction of the CubeSat, and Seth Freeman (Class of 2022), who is working full-time on the project over the summer. Working on thruster development is Jacob Simmonds, a third-year graduate engineering student, whose thesis advisors are Raitses and Yamada. “This project began as a prototype of Yamada’s CubeSat and has evolved into its own project as a testbed for the plasma thruster,” Simmonds said.
Also under construction at PPPL is a test facility designed to simulate key aspects of the CubeSat’s operation. Undergraduates working on their own time are building the satellite and this facility. “To the extent that students and their advisors have identified well-defined questions associated with the TigerSat project, they can get independent work credit,” Marlow said.  “Also, some problem sets in the introductory physics course for undergraduates that I teach have questions related to the TigerSat flight plan.”
Simmonds, while working on the thruster, is drafting a proposal for NASA’s Cubic Satellite Launch Initiative that is due in November. Projects selected by the Initiative, which promotes public-private technology partnerships and low-cost technology development, have launch costs covered on commercial and NASA vehicles. Plans call for a TigerSat launch in the fall of 2021.

Value of collaboration
For Raitses, this project demonstrates the value of Princeton engineering students collaborating with PPPL and of University faculty cooperating with the Laboratory. “This is something that is mutually beneficial,” he said, “and something that we want to encourage.”
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August 01, 2019


 1)      Double-pipe heat exchanger - simplest type of heat exchanger consists of two concentric pipes of different diameters. Following two types of flow arrangement are possible
a)      Parallel flow - both the hot and cold fluids enter the heat exchanger at the same end and move in the same direction
b)      Counter flow - the hot and cold fluids enter the heat exchanger at opposite ends and flow in opposite directions
2)      Compact heat exchanger
a)      Designed to realize a large heat transfer surface area per unit volume
b)      The ratio of the heat transfer surface area of a heat exchanger to its volume is called the area density β. Value of β > 700 m2/m3 are classified as compact heat exchangers.
c)      The large surface area in compact heat exchangers is obtained by attaching closely spaced thin plate or corrugated fins to the walls separating the two fluids.
d)      The two fluids usually move perpendicular to each other, and such flow configuration is called cross-flow. There are two types cross flow
i)        Unmixed flow - plate fins force the fluid to flow through a particular interfin spacing and prevent it from moving in the transverse direction
ii)      Mixed flow - fluid now is free to move in the transverse direction.
3)      Shell-and-tube heat exchanger
a)      Shell-and-tube heat exchangers contain a large number of tubes (sometimes several hundred) packed in a shell with their axes parallel to that of the shell. Heat transfer takes place as one fluid flows inside the tubes while the other fluid flows outside the tubes through the shell.
b)      Baffles are commonly placed in the shell to force the shell-side fluid to flow across the shell to enhance heat transfer and to maintain uniform spacing between the tubes.
c)      Large size and weight hence not suitable for use in automotive and aircraft
d)      Shell-and-tube heat exchangers are further classified according to the number of shell and tube passes involved. Heat exchangers in which all the tubes make one U-turn in the shell
i)        one-shell-pass and two tube-passes heat exchangers
ii)      two-shell-passes and four-tube-passes heat exchanger
4)      Plate and frame (or just plate) heat exchanger
a)      The hot and cold fluids flow in alternate passages and thus each cold fluid stream is surrounded by two hot fluid streams, resulting in very effective heat transfer.
b)      Plate heat exchangers can grow with increasing demand for heat transfer by simply mounting more plates.
5)      Regenerative heat exchanger
a)      Another type of heat exchanger that involves the alternate passage of the hot and cold fluid streams through the same flow area. They are of two types
i)        Static-type regenerative heat exchanger
(1)   Porous mass that has a large heat storage capacity, such as a ceramic wire mesh. Hot and cold fluids flow through this porous mass alternatively. Heat is transferred from the hot fluid to the matrix of the regenerator during the flow of the hot fluid, and from the matrix to the cold fluid during the flow of the cold fluid
(2)   The matrix serves as a temporary heat storage medium.
ii)      Dynamic-type regenerator
(1)   A rotating drum and continuous flow of the hot and cold fluid through different portions of the drum so that any portion of the drum passes periodically through the hot stream, storing heat, and then through the cold stream, rejecting this stored heat. Again the drum serves as the medium to transport the heat from the hot to the cold fluid stream.
(2)   The drum serves as the medium to transport the heat from the hot to the cold fluid stream.


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