Physics Behind Modern 4 Stroke Engines Essay

The energy input (Qin) required to power the internal combustion engines is contained in its fuel. In such engines, the chemical energy of the fuel is mainly converted to shaft energy (BP), energy transferred to the cooling water (Qw), energy transferred to the exhaust gases (Qe) and uncounted losses (Qu) due to radiation, friction, heat transfer to the surrounding, etc.

A turbine is placed in the path of the exhaust gases which are exiting the engine. These gases are caught in the turbine causing it to spin. This spins a shaft along with another pinwheel called the compressor, which is placed in the intake air’s path. This compresses the air on its way into the engine. Normal aspirated engines work to draw in their intake air. As the intake valve opens, the piston’s downward movement creates a vacuum which “sucks” in some air through the intake system. After the work performed by the expansion of the gas in a small space, where the high pressure creates a push against the piston, most of the heat or energy is dumped into the exhaust. This heated air is not in the cylinder long enough to convert all the heat into mechanical energy.

These two engines impact the world in a tremendous way in the transportation industry from driving your cars to work and hauling freight across the

To be specific, an engine uses and operates off of torque. When the air to fuel ratio is ignited, the force on top of the piston (called indicated mean effective pressure) moves the piston down and twists the crankshaft. Since torque is a twisting force, torque directly affects the engine’s performance more than horsepower does. However, once the energy and force reaches the flywheel, some of that energy has already been lost due to friction and heat losses. Friction Mean Effective Pressure, is the term used for all the energy lost to the pistons, connecting rods, crankshaft, and cylinder walls. Consequently, it is FMEP that restricts torque to its full capability, and is a disadvantage of torque in an engine. Conversely, higher horsepower lifts these restrictions off of the engine by adding an extra push, pull, shove, and drag. This in hand, is where horsepower becomes an advantage over torque. A great example of torque versus horsepower is by having two identical vehicles placed side by side, and one of those vehicles has more horsepower, but both have the same toque. Off the line both vehicles would accelerate together because torque is the same, but the vehicle with higher horsepower will eventually start pulling ahead because it has that extra push, pull, drag, and shove to overcome the frictional resistance of the vehicle. On the other hand, the vehicle with less horsepower will be left behind because it doesn't have the extra push to overcome the frictional resistance the vehicle suffers from. As it may seem, horsepower looks to be the better of both worlds, but in reality a good combination of both horsepower and torque is what will be ideal. Since both horsepower and torque will be working together efficiently, it will provide a faster, and smoother driving vehicle that will payoff with a faster time on the track. In conclusion, the question of which is

Complete Cat Back Exhaust: Get more power and better fuel economy with aftermarket exhaust upgrade

To start off you need to know how a rocket engine works. The conventional rocket engine creates thrust by burning a fuel and an oxidizer, such as Liquid hydrogen and Liquid Oxygen. When burnt together in the combustion chamber, the gases created expand and shoot out the nozzle producing thrust which is

The piston is now at the bottom of the cylinder, which is filled with exhaust gases left over from the chemical reaction in the combustion cycle, the rotating crankshaft now pushes upward on the piston, as the piston moves upwards exhaust valves open, allowing the pistons movement to push the gas out of the cylinder so that the engine can start the 4 stroke cycle

Conventional cars use internal combustion engines to generate power to put the car into motion. All conventional cars use what is called a “four-stroke combustion cycle” which are “intake stroke, compression stroke combustion stroke, and exhaust stroke” to

The main issue with the internal combustion engine was its energy transfer efficiency. A large portion of the engines energy was lost through heat and kinetic energy through the exhaust, Alfred Büchi was obsessed with the idea it could be changed. A naturally aspirated engine, also known as N/A, is the engine most cars on the market today have. It relies on the intake stroke of the engine to pull the necessary air into the cylinders and use it for the combustion. The turbo charger is in simpler words a compressor, which uses exhaust fume energy to drive a shaft supplying power to the compressor. The

These types of engines can be found not only in cars and trucks, but in boats, lawn mowers and generators to name a few.

Society is driven by the thought of improving every existing invention to make it bigger, smaller, more cost effective, or simply better. The internal combustion engine has been used in transportation for everyone who lives in a civilized area; whether it is a motorcycle, car, bus, airplane, etc. The most important advances in technology for these engines involve efficiency. Gas mileage, performance, and displacement are key concerns for all engineers of internal combustion engines. With the invention of the turbocharger all of these factors can be improved. The inventor, progression, impact, and current adaptation of the turbocharger are very important in understanding this engineering innovation.

The spark plugs are run by a set of coils, the number of them depends on the amount of cylinders the engine has. The coils receive an electrical current from the engine, and it is run through the distributor which has wires that go to each spark plug. The electricity transfers through the spark plug into the combustion chamber of the cylinder head and ignites the fuel. The cylinder head is where the valves are located. In most internal combustion engines, there are two valves per cylinder. One for the intake of air, and the other to release the gases which are a product of the explosion inside of the cylinder. The valves open and close in synchronization with the pistons in order for the engine to work correctly. There is another part which opens and closes the valves. This part is called the camshaft. The camshaft is much smaller than the crankshaft, and it has lobes which are in offset positions to open and close the intake and exhaust valves at the correct times. The Valves are opened and closed by a set of pushrods for each cylinder. The pushrods are located on top of a part called the lifter. The lifter is what catches the lobes

They design high-performance exhaust headers to increase engine efficiency. This is accomplished by allowing the free flowing exit of exhaust gases after combustion is complete. In

Table 3 provides a summary of the mean piston speed, BMEP and specific power for three different engines. Due to resistance to flow or inertial stresses of moving parts, mean piston speed is limited within 8-15 m/s. Automobile engines usually operate at the higher end of this range, whereas marine engines typically have lower piston speeds (as evident below). In addition, as expected, the BMEP for the 2-Stroke SI marine engine was less than that of the two 4-stroke engines. This is because of

Air subsystem is a key factor in determining torque output and, engine performance. More the cylinder charged with clean air, the higher the maximum possible engine power output. Figure 1 shows the main components of an air subsystem: