Automobile Science

By Parcha Blogpost

Introduction to the science of Automobiles since its advent in 18th century with the steam engine. In order to understand it think of it as process of "fire" converted to "motion". For this article we are limiting the subject on tradtional heat engine model only and not including electric or other models into it. When someone fires a gun it produces kinetic energy which takes the bullet onto its target and also produces recoil towards the firer. When someone lights a cracker-rocket it gets the energy to thurst upwards in the sky from the fire on its behind. Thus, fire produces a jerk on explosion. To catch the kinetic energy repeatedly we need a closed system to keeep repeating the process of the combustion inside it and that is called "engine". Now since we have created a kinetic force we need to make it into smooth comfortable motion. For it needed are gears, clutch, axles, shafts, diffrential and in short the entire power delivery system upto the the tyre. Thus, three main aspects of automobile science are combustion(fire), conversion(engine) and transmission(gears, shafts, axles).

Engines come in a lot of variety. Identified by the fuel used, number of cylinders, arrangement of cylinders, number of strokes etc. The main attribute of an engine is its outputted power in terms of Horse Power or BHP. This is the same kinetic force or energy mentioned above. Net power available at the flywheel which than goes to the gearbox. Now, how engine works in simple terms, at first engine's job is to perform controllable combustion of fuel with oxygen that is done in two ways either by spark plug used in petrol engines or by extreme compression of the mixture of diesel and oxygen almost 13 times to make it blast. When the combustion occurs it sends out huge kinetic energy which pushes the piston and through connecting rods, crank, flywheel that energy reaches the gearbox. Crank's uniform motion and CGI (center of gravity) is fundamental to the performance of an engine. When choosing spare engine especially diesel also check if its giving clean smoke or blacky, in case of blacky it may be sending back compression which means its scrap and not to be purchased at all. Turbo chargers are new items which increase the performance by many folds and the housing pipe and its functioning has to be inspected as well. Set the turbo on 3000 RPM so that it does not affect the mileage when commuting in normal conditions.

Gearboxes - Most vital part of any motor vehicle after the engine is its transmission which is also called gearbox. Gearbox provide two functions to increase torque (power) or to increase speed. How it does it is by combination of two or main gears where one is gear from engine side and another gear is at axle side. If axle side gears is larger than the engine one, it will provide more torque and less speed like first gear. On the other hand if axle gear is small and engien gear is large than it provides more revolutions geenrating more speed and less torque like fifth gear. Famous gearboxes are Leyland T-95, T-85, T-84 and Warner T-98, NGT 520 (Mahindra). Gearbox is an assembly of different gears to make possible the shifting of power mode according to the external conditions, from torque to speed or vice versa. To do that, gears are connected with the aid of a clutch plate to absorb violent jerks and prevent any damage of gears also to give smooth transmission of power mode. Gears have gear ratios, suppose Gear A drives Gear B, how much Gear B will turn upon how much Gear A's turns is what is gear ratio is all about. if B turns more it than A it is in speed mode whereas if it turns less than it is in torque mode. In Automatic Transmission, oil pressure decides the shifting of the power mode. From gearbox the kinetic energy is transmitted to either front axle in case of front powered system like of most cars today or it gets transmitted to diffrential gear at rear through a crown-pinion assembly of drive shaft. From differential gear, the power is transmitted to the wheels and allows both wheels to move freely of each other thus not causing any flow to the motion. For four wheel vehicle, a diffrential gear is placed at front pair of wheels as well. If there is a need to make a plate in order to sync engine with the gearbox than that combination can be avoided and instead choose an engine which is by default compatible with the gearbox. Early jeeps had close gear ratio 3FWD-1REV gearbox which gives more torque and pickup by keeping the vehicle in powerband. It also causes less mileage and also less high speed cruising. These are ideal gear ratios for the jeep's needs and engines such as Perkinson P4, Kirloskar RET4, Mahindra Di 2500 are compatible with them. Toyota 1C, 2C, 3C or Nisaan or HM Isuzu are not meant for these gearboxes.

Blacksmithing

Black-smithing came from very early time but it particularly developed with the discovery of Iron. Israeli-Judea traditions stat that King David (peace be upon him) got this skill directly from the God. Upon the advent of Iron-Age some 1500BC use of Iron followed by the steel which was mixture of Iron (Fe) with miniscule amounts of carbon 0.015% to 01%, became the mark of technology of the era. Iron was and is one of the most durable, strong and useful element. Steel comes in three main varieties such as low carbon steel, mild carbon steel or high carbon steel. Abbreviations as MS,HS,LS denote this on a steel. low carbon steel is used in construction works, mild steel is used in leaf-spring and other springs bearing excellent durability and tensile strength. High carbon steel is hard and is used for kitchen knives, Katana Swords, metal-files, cutting saw and blades. High Carbon steel can be bought from suppliers or scavanged from old files, saw blades, cutter discs. When comparing Mild steel vs High carbon steel, mild steel has more tensile strength and less prone to breakage but at the cost of less sharpness. To get the perfect combination a Japanese technique of "partial hardening" is performed especially over Katana Swords but it can be used on knives as well. In this technique, clay or any insulating paste is applied on High carbon steel at its back to protect it from furnace heat whereas edge is exposed to heat and suddenly quenched in water to make it hard while the backbone remains soft and less prone to breakage. When it gets done, the less hard part and hard part act as suspension absorbing shocks with no compromise in sharpness. Thus, good of both the worlds is achieved.

Age of exploration, renaissance and colonies

Magnetic Compass is a simple device which consist of a magnetic needle that points to the Earth's magnetic north and this means that now a reliable navigating tool was available to the people who use to observe stars, winds, sunrise and sunset for the same which was tiring, not so accurate and was complicated. First use of magnetic compass started in China after 1000 CE and from there it went to Europeans and Arabs. In the 1400's Portugese made the light ship called "Caravel" with triangular Latin sales, rudder and were also equipped with magnetic compasses and sextants to accurately and swiftly traverse the unknown waters. Henry the Navigator, Vasco De Gama, Christopher Columbus and many other explorers went on expidition uncovering the african continent linking to India and Malacca region in East and America, Latin America and the Carribean in the West. In another story a sailor named Ferdinand Magellan (1480-1521) who was a Portuguese explorer who led the first expedition to circumnavigate the globe meaning covering the entire earth from east to west or vice versa. In 1519, Magellan sailed west with five Spanish ships to find the Spice Islands. He discovered the Strait of Magellan and became the first European to cross the Pacific Ocean. Magellan was killed on the voyage in what is now the Philippines. Only 22 of the original 270 crew members made it back to Europe. Magellan was sponsored by Spain to travel west across the Atlantic in search of the East Indies. He was convinced that by sailing west instead of east, he could map a new route to Indonesia and India. Magellan abandoned his Portuguese loyalty and headed to Spain, where he gained citizenship and King Charles V's blessing for a five-ship journey westward. They instead of sailing east around the cape of good hope southern tip of Africa, taking a brave step they rather went in the westward direction sailing across the Atlantic to the South America and at first reaching its South most tip. There because of cold winters they took a halt by anchoring their ships and after several month when the conditions were favourable they resumed the journey sailing around the tip of South America towards West and after sailing in the Pacific for several months while low on food and other supplies they reached modern day Phillipines. On April 27, 1521, Portuguese explorer Ferdinand Magellan was killed by a poison arrow during a skirmish on the island of Mactan in the Philippines. From their Juan Sebastián del Cano lead the voyage to Malay islands where they bought the spices and travelled westward to Africa and reaching the islands of Cape Verde in the Atlantic where they under disguised rested and acquired the supplies. There they got to know about the date error because of different time zones as their calander said it was Wednesday and in local place it was rather Thursday. Thus, they circumvented the globe by starting the journey from Cape Verde vicinity and ending it there all by travelling in a single direction of West. Many of their crew revolted during the voyage upon it many were killed and some deserted and survivors had to return to the Maluku islands, where they and the Trinidad were captured by the Portuguese. The scinetific discoveries done in the event of these explorations were remarkable and had placed these Europeans much ahead of their counterparts in middle-east, asia and africa. This led to monopoly of maritime trade for them. Following many years these Europeans made many other scientific achievements which eventually led to "colonial age".

Chandrayan 3 India's Successful Lunar Mission

Chandrayan 3 is a space probe mission of India intended to send probe vehicle to Moon and land safely than rove over the surface of the Moon. In the past, Chandrayaan-1, launched on 22 October 2008 aboard a PSLV-XL rocket, was a big success for ISRO as the Moon Impact Probe, a payload on board the Chandrayaan-1 spacecraft, discovered water on the Moon. Apart from detecting water the Chandrayaan-1 mission performed several other tasks such as mapping and atmospheric profiling of the Moon. On 18 September 2008, the First Manmohan Singh Cabinet approved the mission. Although ISRO finalised the payload for Chandrayaan-2 per schedule, the mission was postponed in January 2013 and rescheduled to 2016 because Russia was unable to develop the lander on time. Roscosmos later withdrew in wake of the failure of the Fobos-Grunt mission to Mars, since the technical aspects connected with the Fobos-Grunt mission were also used in the lunar projects, which needed to be reviewed. When Russia cited its inability to provide the lander even by 2015, India decided to develop the lunar mission independently and unused orbiter hardware was repurposed to be used for Mars Orbiter Mission. Chandrayaan-2 was launched on 22 July 2019aboard a LVM3 rocket. The spacecraft was successfully put into lunar orbit on August 20, 2019 but the lander was lost while attempting to land on 6 September 2019. Finally Chandrayan 3 landed on 1804 IST on Wednesday 23rd August 23. Now India joins the lunar landing club of USA, Russia and China. India is the only one to make landing at the South Pole of the Moon.

Industrial Revolution, powered by steam

In 1784, William Murdoch, a Scottish inventor, built a small-scale prototype of a steam road locomotive in Birmingham. A full-scale rail steam locomotive was proposed by William Reynolds around 1787. An early working model of a steam rail locomotive was designed and constructed by steamboat pioneer John Fitch in the US during 1794. The first full-scale working railway steam locomotive was built by Richard Trevithick in the United Kingdom and, on 21 February 1804, the world's first railway journey took place as Trevithick's unnamed steam locomotive hauled a train along the tramway from the Pen-y-darren ironworks, near Merthyr Tydfil to Abercynon. Steam engine including engines for trains, ships, factories, mills, water pumps, domestic fans, electric generators truly revolutionalized the Britain giving it emmense money and power by rapid production and growth which was because of the use of these machines. Iron and coal abundant in its colony of India were extracted and used to make various things and than sell it in the world market. Coming to its technical aspect with brief history that steam engines were in existance in some form right from 2 CE Rome to 1500s Ottoman Turks to sometimes in Spain. However, only Britain could develop them up to the point where it can power an empire and that too of a size that sun never sets in it. Steam engine consist of a fire making furnace and a container called boiler where water converts into steam upon the heat. This steam is produced upto some predesignated pressure like 1700 times or 8 bar or anyhting depending upon the application. Steam is channeled to a cylinder where it pushes the piston head in order to escape, by doing this piston generates kinetic energy which rotates the crank and thus creating a motion. This motion can be used in different applications like running of a water pump, textile mill, factory machines, train's engine, ship's engine, bus's engine, tractor etc. Great Britan with all the riches it acquired over a century by its maritime trade activities around the globe and colonies as India, South Africa, UAE, Malay which provided for its raw material needs in abundance was set to trigger an Industrial revolution. Factories of Manchester, Lancashire, East London, Scotland were made with new steam boilers and upon that supervisors and labourers were also trained in the new technology. Whislt ships laden with raw material kept coming from the colonies on to the sea-ports of the Britain. The transportation problem was also solved by the same steam by the invention of the steam engine based locomotive and train system used to drive rail-carriages, full of raw material and/or coal-fuel from the ports to factories. Coal became the fuel of the age and soon coal mines were seen as lucrative business. How science shapes the history can be seen in this story. Science of cultivating steam to meet the needs of mankind resulted in the Industrial revolution of 18th centruy and upon it the need of labourers and supervisors grew which saw the woman workers acceptable in the society. This brought terms such as cosmopolitan, gender equality, work culture to the society and gradually feudal Europe was transformed into manufacturing hub of the world. Its profound impact can be seen today, in context of India Punjab, Bengal and Gujrat were greatly industrialized while Uttar Pradesh and Rajasthan remained feudal. In today's life where most of the steam enabled devices have become obselete yet we see a great device which is still use to run on the steam and present in most households today and that is the "pressure-cooker" which has greatly helped the homemakers by reducing the cook time and effort.

Computer Science

Computer science in a nutshell means ability to process any data or information. Computation means processing of something like calculation, word processing, printing, typing etc. What it does basically is to mimic a human brain in this way. How you would tell a very real dumb child to do something ? by breaking your statemnt into simple instructions like stand, sit, walk, run, jump, lay, eat, drink, sleep etc. These instructions form the basis of computer programming called the commands. As we talk in many languages like English, Hindi, Bhojpuri etc similarly computers have different languages with all having more or less, the same commands in them. These language are C, C++, Python, Java, C#, PHP, R, MATLAB etc. As in India, we speak mostly Hindi and in Japan they speak Japanese. In same way every domain or platform has its own language because of utlities and ease of work it offers for that particular domain. For instance, java is good for mobile android development, php for simple websites, Python for aritifcial intelligence and C/C++ for fast execution robotics or embedded systems. So a computer engineer has to be well versed in number of languages and not one. Programming starts by building logic and the process is called algorithm comprising of few to many steps of instructions or commands given to the central processign unit. These basically contain the basic dumb commands, loops, array and matrix handlers and conditional statements like if, else, than. This code gets broken down into a binary code which is in 0,1 by a process called compilation done by the compiler or in some cases interpreter. Binary code is nothing but representation of different voltages marke by 0 or 1 like 0 for 5v and 1for 12v as computer being an electronic device only understands the voltage. Frequency of a processor is measure of how many instances of these voltage differences a computer can read in a second. A 2.4 GHZ Processor can read 2.4 * 1,000,000,000 (billion) voltage readings per second. While RAM or ROM is a memory that is coupled with the processor like how a train's steam engine is coupled with the coal wagon attached just behind it. The processor is like the train steam engine, ram is the coal wagon from where it can draw additional coal and the wagon does the coal storing intended for immediate use whereas a hard drive works as large repository of coal from where these wagons get supplied inturn. In this case of computer you can think of coal as memory registers present in the CPU which can be 8-bit , 16-bit, 32-bit or 64-bit which are slots for storing addresses of memory locations on the RAM and the Ram is loaded with the data from the hard drive. This is analogous to the case of coal burning inside the steam engine while some is stored in coal wagon as cash coal for immediate use and remainder is at railway station repository. Internet is a network through which many computers talk with each other by sending and receiving data bits. Computer is used for processing information, calculations, task specific jobs, entertainment and arts. Thus it is a necessary part of today's world.

Drive Train - Differential Mechanism

Lets first understand basic concept of a rotating disc or a gear or pendulam or be it anything. When an object rotates in a plane x-y axise's, imagine that a table's top is that plane and kitchen plate is a disc which rotates upon it. It is worth noticing that the rotation exerts all forces in x-y plane that is in all sides of the table's top but nothing happens on plate's upside or downside in the z axis which is perpendicular to the x-y plane. Therefore, if this system arrangement is used in gears we can achieve a setup where any gear lying in z axis will not get affected by the ones in x-y and when we need it to get affected we can shift it from being in z axis to x-y. This is the basic principal behin diffrential gears. The basic components of a differential are: A ring gear: This is the largest gear in the differential and is attached to the driveshaft. A pinion gear: This gear is smaller than the ring gear and meshes with it. It is driven by the ring gear and turns the spider gear. A spider gear: This is a small gear that is located between the two side gears. It is free to rotate on its own axis and is driven by the pinion gear. Two side gears: These gears are attached to the axles and are driven by the spider gear. When the vehicle is driving straight, the pinion gear rotates at the same speed as the ring gear. This means that the spider gear does not rotate and the two side gears rotate at the same speed. For automobile a differential is a mechanism that allows the wheels of a vehicle to rotate at different speeds, even when they are connected to the same driveshaft. This is necessary for vehicles to turn corners smoothly, as the outer wheel will need to travel a greater distance than the inner wheel.When the vehicle turns, the outer wheel needs to travel a greater distance than the inner wheel. This means that the outer wheel needs to rotate faster than the inner wheel. The differential allows this to happen by allowing the spider gear to rotate on its own axis. The amount of speed difference between the two side gears is determined by the amount of torque applied to the wheels. If the outer wheel is applying more torque than the inner wheel, the spider gear will rotate in the opposite direction and the outer wheel will rotate faster. Differentials are an essential part of all vehicles with more than one driven wheel. They allow vehicles to turn corners smoothly and safely. Here are some additional things to know about differentials: There are two main types of differentials: open differentials and limited-slip differentials. Open differentials allow the wheels to rotate at different speeds without any restrictions. Limited-slip differentials allow the wheels to rotate at different speeds, but they also apply some braking force to the wheel that is spinning faster. This helps to prevent the wheels from slipping. Differentials can be found in a variety of vehicles, including cars, trucks, motorcycles, and buses. Differentials are a complex mechanism, but they are essential for the safe and efficient operation of vehicles. Image or video credits: https://www.tec-science.com/mechanical-power-transmission/planetary-gear/how-does-a-differential-gear-work/