DIY - Car maintenance

ietor, such costs not being taken into account when the proprietor opts to drive their car. According to the Harvard University,11 the main externalities of driving are local and global pollution, oil dependence, traffic congestio

DIY - Car maintenance best stop smoke oil treatment

Basic knowledge - Public costs

The external costs of automobiles, as similarly other economic externalities, are the measurable costs for other parties except the car proprietor, such costs not being taken into account when the proprietor opts to drive their car. According to the Harvard University,11 the main externalities of driving are local and global pollution, oil dependence, traffic congestion and traffic accidents; while according to a meta-study conducted by the Delft University12 these externalities are congestion and scarcity costs, accident costs, air pollution costs, noise costs, climate change costs, costs for nature and landscape, costs for water pollution, costs for soil pollution and costs of energy dependency. The existence of the car allows on-demand travel, given, that the necessary infrastructure is in place. This infrastructure represents a monetary cost, but also cost in terms of common assets that are difficult to represent monetarily, such as land use and air pollution.



Źródło: https://en.wikipedia.org/wiki/Economics_of_car_use


2-stroke engines

2-stroke engines
Main article: 2-stroke engine

The defining characteristic of this kind of engine is that each piston completes a cycle every crankshaft revolution. The 4 processes of intake, compression, power and exhaust take place in only 2 strokes so that it is not possible to dedicate a stroke exclusively for each of them. Starting at TDC the cycle consist of:

Power: While the piston is descending the combustion gases perform work on it?as in a 4-stroke engine?. The same thermodynamic considerations about the expansion apply.
Scavenging: Around 75° of crankshaft rotation before BDC the exhaust valve or port opens, and blowdown occurs. Shortly thereafter the intake valve or transfer port opens. The incoming charge displaces the remaining combustion gases to the exhaust system and a part of the charge may enter the exhaust system as well. The piston reaches BDC and reverses direction. After the piston has traveled a short distance upwards into the cylinder the exhaust valve or port closes; shortly the intake valve or transfer port closes as well.
Compression: With both intake and exhaust closed the piston continues moving upwards compressing the charge and performing a work on it. As in the case of a 4-stroke engine, ignition starts just before the piston reaches TDC and the same consideration on the thermodynamics of the compression on the charge.

While a 4-stroke engine uses the piston as a positive displacement pump to accomplish scavenging taking 2 of the 4 strokes, a 2-stroke engine uses the last part of the power stroke and the first part of the compression stroke for combined intake and exhaust. The work required to displace the charge and exhaust gases comes from either the crankcase or a separate blower. For scavenging, expulsion of burned gas and entry of fresh mix, two main approaches are described: Loop scavenging, and Uniflow scavenging, SAE news published in the 2010s that 'Loop Scavenging' is better under any circumstance than Uniflow Scavenging.6

Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine


Gas turbines

Gas turbines
Main article: gas turbine
Turbine Power Plant

A gas turbine compresses air and uses it to turn a turbine. It is essentially a Jet engine which directs it's output to a shaft. There are three stages to a turbine: 1) air is drawn through a compressor where the temperature rises due to compression, 2) fuel is added in the combuster, and 3) hot air is exhausted through turbines blades which rotate a shaft connected to the compressor.

A gas turbine is a rotary machine similar in principle to a steam turbine and it consists of three main components: a compressor, a combustion chamber, and a turbine. The air, after being compressed in the compressor, is heated by burning fuel in it. About ? of the heated air, combined with the products of combustion, expands in a turbine, producing work output that drives the compressor. The rest (about ?) is available as useful work output. 26

Gas Turbines are among the MOST efficient internal combustion engines. The General Electric 7HA and 9HA turbine electrical plants are rated at over 61% efficiency. 27

Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine