ET213: Project in the engineering environment 4 Stroke engine cycle 1) This cycle is known as intake or suction, the pistonis at (T.D.C) top dead centre and finishes at (B.D.
C) bottom dead centre as thepiston moves down the intake valve is open sucking in air ready for the fuelmixture.2) The compression cycle is where the piston andthe pressure created compresses the air and fuel mixture(14.7:1) air to fuel ,ready for igniting this is done with the intake and exhaust valve closed. 3) This combustion cycle is normally known as ignitionthis is when the piston has had its second revolution and the crankshaft hasmade a full 360 degrees. When the piston is on T.D.C the fuel and air mixtureis ignited via the sparkplug and forcing the piston to B.
D.C when both valvesare closed. 4) This cycle is known as the exhaust or outlet when thepiston returns from B.D.C to T.D.
C and when the exhaust valve is open thepiston forces the air and fuel mix out. Advantages Disadvantages They are very reliable due to the piston not going around as much as a two stroke has high rpm firing the piston rapidly around. They are very heavy They have believed to show more torque and quicker. Complex in the way it is manufactured They run very clean duo to the air and fuel and oil being separated until it needs to be used however the two stoke have oil mixed with fuel. Petrol and diesel DieselIna diesel engine there is no need to ignite the fuel via a spark plug in factthe fuel is ignited duo to the heat and friction of the engine, grid heaters and block heaters help achievehigh temperatures for combustion during engine start up in cold weather. Diesel is made from distilled oil and otherproducts as is petrol that will eventually run out of materials.
Ø A diesel-powered engine can delivery up to 25 to 30%better fuel economy compared to vehicles powered by petrol engines.Ø Diesel cars are much slower but they are far strongercompared to gas-powered vehicles.Ø Disadvantages diesel costs just as much as petrol andthe performance of diesels aren’t as good as petrol not going as fast.
Ø They also need a lot of maintenance which isn’t goodas well due to them being very complex. PetrolPetrolis made from oil like diesel that will also run out if we continue using it atthe rate we do and we will have to find a different source of power orpropulsion for our vehicles that I will explain about soon. And this petroldoes have to include a source of ignition like a sparkplug.
Ø This can produce a lot of energy exactly 10,000kilocalories when burned.Ø They have perfectly adjusted the formula duo to itbeing existed for a long while.Ø Since petroleum has been around for some time, peoplehave found a lot of uses for it. It can now power cars, trucks, boats, andother kinds of vehicles as well as machines that are used in manufacturing andother industries.BIGGESTDISADVANTAGEØ It can lead to environmental pollution.Extractingthis produces a substantial amount of toxic materials. If these are improperlydisposed, they can soak into the ground and spread harmful chemicals that canpollute rivers and streams and kill animals. Burning petrol gives of largeamounts of carbon dioxide and other gases, which can pollute the air,contribute to the greenhouse effect, and lead to global warming.
.. Eventuallywe will run out of oil however there is a debate on how long that will be. Hybrid cars Ahybrid car is one that uses more than one means of propulsion. The definition of hybrid is combining two elementsinto one.
A hybrid car is combining a petrol powered engine with an electricmotor. Hybrid vehicles use their petrolpowered engine as their main energy source, and use their electric engine tocollect and reuse energy that normally goes to waste in a non-hybrid car. Onthe other hand, in a plug-in hybrid vehicle, the petrol powered engine is onlyused as a back-up when the electric engine’s batteries run out of charge.EXAMPLES OF HYBRID CARS What do hybrid carscost?Going green to help savethe environment comes at a price – and it’s not a small one. Hybrid cars aregenerally a few thousand dollars more than their counter cars, generallyranging from £2,000-£5,000 more. If you normally travel short distances anddon’t use a lot of gas, buying a hybrid may not be the best financial decisionfor you.
This is because it could take years for you to save at the pump whatyou will pay up-front for the hybrid portion of the car. On the other hand, if you have a long commuteto work and have to stop a couple times a week to fill up, then you could besaving a lot of money over the course of a single year with less frequent gasstation stops. Hybrid petrol run and electric backs upPlug in hybrid electric and petrol backs upPetrol engine diesel the same The main advantages of a hybrid are that ituses less fuel and emits less CO2 than most conventional non-hybrid vehicles.
Because of this, ownersalso get extra benefits in the shape of lower rates of road and company cartax, as well as possibly avoiding congestion charges. However there are somemore……… ADVANTAGES1. EnvironmentallyFriendly: One of the biggest advantages of hybrid car over petrol powered caris that it runs cleaner and has better mileage which makes it more efficient.2. Built FromLight Materials: Hybrid vehicles are made up of lighter materials which meanless energy is required to run. The actual engine is also smaller and lighterwhich also saves much energy and money.
3. Lessdependence on Fossil Fuels (as in wont need as much): A Hybrid car is muchcleaner and requires less fuel to run. This in turn also helps to reduce theprice of petrol in domestic market. DISADVANTAGESNot as much power: Hybrid cars are twin poweredengine. The petrol engine which is primary source of power is much smaller ascompared to what you get in single engine powered car!!!! and electric motor islow power anyway.
Can be Expensive! The biggest backlash of having ahybrid car is that it may as well steal your money. Hybrid cars arecomparatively expensive than a regular petrol car and can cost £2000 to £5000more than a standard version. Full electric and plug inIn thestandard electric car a current is sent to the motor from a battery which inturn spins and propels the wheels.
On estimate an electric car can run up to140 miles of charge and then has to be plugged back in however a hybrid you cancharge on the go so which one is better. Well hybrids are still not a fullsource of sustainable energy so what do you do? Therefore they (scientists) arefiguring out a way of being able to charge your full electric car wherever yougo instead of only getting 140+ miles. But this still needs to be sustainable.By plug in I mean(they mean) instead of putting petrol into your vehicle yousimply plug a lead from a source via a car park or your home which willhopefully be everywhere in the future into you car. Basically like you charge amobile phone with a lead. Cheaper to maintainAselectric cars don’t need oil changing or added oil you don’t need to pay fornew oil furthermore with been electric there is no need to pay out for petroland diesel every time you travel and have to charge it instead. However it willneed charging which will not cost nearly ¼ as much as petrol and diesel butwill not get you as far.
They also don’t suffer routine breakdowns and don’tneed any gaskets for oil or liquids if they blow or break. This is normallybecause there are fewer moving parts. In fact oil needs changing every3000-5000 miles. Better for the environmentElectriccars do not emit any basses or any greenhouse gasses effecting the environmentsatmosphere.
This would really be a help in city centres duo to the fact theyare many cars polluting there so e-cars would benefit there the most. Howeverif charging these cars involve burning fossil fuels these benefits are limited. Reduced Noise PollutionElectriccars put a stop to noise pollution as they are much quieter. Electric motorsare capable of providing smooth drive with higher acceleration over longerdistances. Little range on full chargeElectriccars are limited by range and speed. Most of these cars have range about 50-100miles and need to be recharged again.
You just can’t use them for long journeysas of now, although it is expected to improve in future. Furthermore they arelittle amounts of recharge points which are also duo to improve in the futureas for now they aren’t many which doesn’t push you towards buying them. Little space in carThesenew electric cars have little room and have commonly known only to have acouple of seats which is not ideal for big families or ones with children up totwo seats.
It also doesn’t have much room in the boot for space either so nocompany’s would benefit from these. Battery ReplacementDependingon the type and usage of battery, batteries of almost all electric cars arerequired to be changed every 3-10 years.Thereare many other disadvantages but these are the main… Why do we need analternative propulsion system?PollutionDue to petrol cars letting out millions of emissionslike carbon dioxide every day its killing the earth and the population ofanimals. These harmful exhaust emissions consist of (carbon monoxide,particulate matter such as sulphur dioxide). Going into detail when they enterthe atmosphere greenhouse gasses have formed around the earth trapping theseother exhaust gasses in heating up the earth.
When the earth heats up the icemelts raising the sea levels destroying habitats and causing globalwarming. Conventionalfuels are going to run outSources that create these fuels and oils are goingto run out they are not one bit sustainable. When the demands for these becometo rations the worry is it will start a world crisis. Every country is tryingto find a new resource. Toprotect against global warmingAs I have said fossil fuels are causingtemperatures to rise in the earths atmosphere, people are saying they wantcleaner energy to protect the earth.
Tosave moneyAlternativefuels can be less expensive to use not just in terms of the fuel itself butalso in terms of a longer service life. This in turn means savings for the longterm. More convenienceTheyhave already made cars more convenient by making the electric cars chargewirelessly. Nissan have already displayed there new technology that goes by thename parking assist which does what is says on the tin guides the vehicle intothe spot/charging dock.
All you have todo is press a button these are more convenient to putting petrol in the vehicleand driving your car into a space. Duo to a car having more and more sensorsthe task of driving the car have reduced a lot and some people say that itsmade them more safe. Modified cruise speeds have been created for motor waysand other roads.
Emergency stop, GPS navigation when you think of cars now theyhave advanced millions and it keeps going especially when these new sources ofpropulsion have been developed. Myconclusion and idea of future propulsion How do youthink propulsion systems will develop?What systemis best petrol diesel y? Optionsbetween Petroldiesel hybrid pure electric nitrogen