What are the dynamic and economic indicators of the engine?

The dynamic index of the engine is an index that indicates the functional force of the engine, and the effective torque, effective power, engine speed, and liter power can be used as evaluation indicators.

The engine economy index is generally expressed by the effective fuel consumption rate, and the amount of fuel consumed by the engine per 1kw·h of effective work (in g) is called the effective fuel consumption rate.

Thrust is the most important performance indicator of an engine.

Engine thermal efficiency, propulsion efficiency, total efficiency.

Thermal efficiency: the ratio of mechanical work to the heat emitted by the complete combustion of engine fuel.

Propulsion efficiency: The ratio of propulsion work to available work is also equal to thrust multiplied by flight speed.

Total efficiency: The ratio of the work of propulsion to the heat emitted by the complete combustion of the fuel is also equal to the product of the thermal efficiency and the efficiency of the propulsion.

Measure economy in terms of total efficiency.

Fuel Consumption Rate: The amount of fuel consumed per pound of thrust per hour An important economic indicator.

Important engine parameters: EPR, N1, EGT

EPR: Engine Pressure Ratio The ratio of the total outlet pressure of the low-pressure turbine to the total inlet pressure of the low-pressure compressor For turbofan engines of axial compressors, it characterizes the thrust.

n1: fan speed For turbofan engines with high bypass ratio, the thrust generated by the fan accounts for the vast majority, so n1 is also a thrust characterization parameter.

EGT: Exhaust temperature The total turbine inlet temperature is one of the most important parameters of the engine, but it cannot be measured, so the turbine exhaust temperature is used to indirectly reflect the limit of the EGT to ensure that the turbine inlet temperature does not exceed the limit.

1.Motivation indicators.

The dynamic index is an index that characterizes the functional force of the engine, and the effective torque, effective power, and engine speed of the engine are generally used as evaluation indicators.

1) Effective torque.

The torque output of the engine is called the effective torque, 2) the effective power.

The effective work output of the engine per unit time is called the effective power, 3) the engine speed.

The number of revolutions per minute of the engine crankshaft is called the engine speed, 2Economic indicators.

Engine economy indicators are generally expressed in terms of effective fuel consumption rate. The amount of fuel consumed by the engine per 1 kW·h of effective work (in g) is called the effective fuel consumption rate.

The Science of Internal Combustion Engines" by Zhou Longbao, Chapter 2, Section 5 is it.

1. Pressurization. 2. Organize combustion and improve the efficiency of indication.

3. Increase the charge coefficient.

4. Increase the speed.

5. Improve mechanical efficiency.

6. Use 2-stroke (actually no one uses it).

Economy index: Engine economy index is generally expressed by effective fuel consumption rate. The amount of fuel consumed by the engine per 1 kW·h of effective work (in g) is called the effective fuel consumption rate.

Dynamic index: The dynamic index is an index that characterizes the functional force of the engine, and the effective torsional torque, effective power, and engine speed of the engine are generally used as evaluation indicators.

The engine is the ability to learn from the Xiang faction.

Converted into mechanical energy.

The transformation process of the machine is actually the process of the work cycle, simply put, it is through the combustion of the fuel in the cylinder, generating kinetic energy, driving the reciprocating motion of the piston in the engine cylinder, thereby driving the connecting rod connected to the piston and the crank connected with the connecting rod around the crankshaft.

The center moves in a reciprocating circular motion.

And the output of power.

1. Body: It is the assembly base of each part of the engine. It includes the cylinder head, cylinder block, lower crankcase (oil pan). The cylinder head and the inner wall of the cylinder block together form part of the combustion chamber. Many parts of the body are part of other systems.

2. Crank connecting rod mechanism: It is a mechanism by which the engine generates and transmits power, through which the linear reciprocating motion of the piston is transformed into the rotary motion of the crankshaft.

Output power. It includes pistons, piston pins, connecting rods, crankshafts with flywheels, and cylinder blocks, among others.

3. Fuel supply system: gasoline engine.

The fuel supply system includes a gasoline tank, a gasoline pump, a gasoline filter, and an air filter.

Carburetors, intake pipes, exhaust pipes, exhaust mufflers, etc. Its function is to mix gasoline and air into a suitable combustible mixture and supply it to the cylinder for combustion, and exhaust the exhaust gas generated by combustion out of the engine.

The economic performance index of the engine is generally expressed in terms of thermal efficiency, which is the effective energy utilization rate during the combustion process of the engine.

The percentage of the heat generated by the combustion of a fuel that is converted into effective work is called the effective thermal efficiency of the fuel and is denoted as e. Obviously, the less heat is expended to obtain a certain amount of effective work, the higher the effective thermal efficiency, and the better the economy of the engine.

The performance index of the head engine is used to characterize the performance characteristics of the engine, and is used as the basis for evaluating the performance of various engines. The failure chain performance indicators of the engine mainly include: dynamic indicators, economic indicators, environmental indicators, reliable wheel indicators and durability indicators.

The economy of the car engine and the effective fuel consumption are measured.

1. Effective torque, the torque output of the engine is called effective torque, that is, the torque of the engine. Generally, the greater the torque of the engine, the stronger its acceleration ability and climbing ability. Generally, the larger the bore of the engine, the longer the piston stroke, and the greater the torque of the engine.

This is also one of the reasons why large displacement engines have more torque.

2. Effective power, the effective work output of the engine per unit time is called effective power, that is, the power of the engine, which is equal to the product of the effective torque and the angular velocity of the crankshaft. Engine power is the most important indicator of engine performance, and the top speed of a car is determined by engine power.

3. Engine speed, the number of revolutions per minute of the engine crankshaft is called engine speed. The speed of the engine is related to the number of work times per unit time or the effective power of the engine, that is, the effective power of the engine changes with the different speeds. Therefore, when indicating the effective power of the engine, its corresponding speed must also be indicated.

4. The average effective pressure, the effective work emitted by the working volume of the unit cylinder is called the average effective pressure, the greater the average effective pressure, the stronger the working force of the engine. Many engines are turbocharged today, and the average effective pressure is higher than that of naturally aspirated engines.

The three indicators of the power of the car are: 1. What is the maximum driving speed of the car; 2. The ability of the car to quickly increase the driving speed while driving; 3. The climbing ability of the car is the maximum slope that can be crawled in the lowest forward gear.

Three indicators that prove the power of the car.

1. The maximum speed of the car refers to the maximum speed of the car on the road surface with a straight road and a good line of sight, and what is the maximum speed that the car can achieve; It is denoted by km h.

2. The acceleration ability of the car, the acceleration ability of the car refers to the ability of the car to rapidly increase the driving speed while driving. In general, the acceleration of starting on the spot and overtaking is evaluated.

1) In-situ acceleration refers to the time required for the car to accelerate with the maximum acceleration intensity after starting, and appropriately select the most favorable gear shift time, and gradually shift to the highest gear to reach a certain predetermined distance or speed. Generally, it is usually expressed as the time required from 0-400m; It can also be expressed in terms of the time required from 0 to 100 km h.

2) Overtaking acceleration. Automobile speeding refers to the time it takes for a car to accelerate at a certain high speed from a predetermined speed (the lowest stable speed of the gear or 30 km h) in the highest or second high-end gear.

3. The climbing ability of the car. The climbing ability of a car is the maximum gradient that a car can climb in the lowest forward gear on a good road surface when fully loaded.

Engine economy indicators include effective thermal efficiency and effective fuel consumption rate. 1.Effective Thermal EfficiencyThe percentage of heat generated by fuel combustion converted into effective work is called effective thermal efficiency and is denoted as e, obviously, the less heat consumed to obtain a certain effective work, the higher the effective up-cracking thermal efficiency, and the better the economy of the engine.

2.Effective Fuel Consumption RateThe amount of fuel consumed by the engine per 1kW of effective work output is called the effective fuel consumption rate, which is denoted as BE, and the unit is G (kWh). where:

b——Fuel consumption of the engine in the unit hour source room, kg h; PE - the effective power of the engine, kW. Obviously, the lower the effective fuel consumption rate, the better the economy.

The performance indicators of the engine mainly include power indicators, economic indicators, environmental indicators, reliability indicators and durability indicators. The relevant information about the Engine Performance Index is as follows: Introduction to the Engine Performance Index:

The engine performance index is used to characterize the performance characteristics of the engine and is used as a basis for evaluating the performance of various engines. The performance indicators of the engine mainly include power indicators, economic indicators, environmental indicators, reliability indicators and durability indicators.

The performance index of the engine shows that the power index is the index that characterizes the working capacity of the engine, and the effective torque, effective power and engine speed of the engine are generally used as the evaluation index. Engine economy indicators are generally expressed in terms of effective fuel consumption rate.

The amount of fuel consumed by the engine per 1 kW·h of effective work output (in g) is called the effective fuel consumption rate. Environmental indicators refer to the exhaust quality and noise level of the engine. Because it is related to human health and the environment on which it depends, countries around the world have formulated strict control regulations in order to reduce the pollution of engine exhaust and noise to the environment.

At present, emission indicators and noise levels have become important performance indicators for engines. The reliability index is an index that characterizes the ability of the engine to work normally and continuously under the specified conditions of use and within the specified time. There are many ways to evaluate reliability, such as mileage to first failure, mean mileage between failures, etc.

The durability index refers to the limit time that the main parts of the engine are worn out and cannot continue to work normally.

The main performance indicators of the engine 1, dynamic indicators.

1) Effective torque (t+4) (unit.

The torque that is output from the engine through the flywheel.

2) Effective power (PE denomination, unit kW).

a. Definition: The output power of the engine through the flywheel is called the effective power of the engine.

b. Calculation formula:

3) Engine product nameplate.

a. Rated power and rated speed: The power and corresponding speed indicated on the nameplate of the engine product are called rated power and rated speed.

b. Calibrated power classification: 15 minutes power, 1 hour power, 12 hours power, continuous power.

Among them, 15 minutes of power is commonly used as the calibrated power in the car.

2. Economic indicators.

1) Expression method: fuel consumption rate (2) Definition: refers to the mass of fuel consumed by the engine in 1 hour for every 1kW of effective power emitted

3) Requirements: The lower the fuel consumption rate, the better the fuel economy.

4) Calculation formula:

3. Engine speed characteristics (1) definition: the law of the change of engine power, torque and fuel consumption rate with crankshaft speed.

4) Partial characteristics of the engine: The speed characteristics obtained in addition to the full opening of the throttle are called partial characteristics.

5) External engine characteristic curve diagram.

4. Engine working conditions and loads.

1) Working condition (engine working condition): Generally, it is characterized by the power of the house and the speed of the crankshaft, or it can also be expressed by the load and the speed of the crankshaft.

2) Load: The ratio (%) of the power emitted by the engine at a certain speed to the maximum power that can be emitted at the same speed

5. Classification of engine performance indicators.

There are two main indicators of engine performance, one is power and the other is torque.

The unit of power is kilowatt or horsepower, and the unit of torque is Nm.

In layman's terms, power reflects the absolute speed of the car, or how fast it can run; Torque reflects acceleration, which is the energy to speed up. Generally speaking, a powerful engine can run very fast, and it is possible to reach speeds of up to km/h. The engine with high torque has good acceleration performance, fast acceleration and flexibility.

1. Effective torque: refers to the torque output by the engine through the crankshaft or flywheel.

2. Effective power: refers to the power output of the engine through the crankshaft or flywheel.

3. Crankshaft speed: refers to the number of revolutions per minute of the engine crankshaft, usually expressed by n, and the unit is r min.

Extended content: Car maintenance precautions:

1.Clean the air filter.

If the air filter is blocked or too much dust accumulates, it will cause the engine to be poorly intake, and a large amount of dust enters the cylinder, which will accelerate the speed of cylinder carbon deposition, so that the engine ignition is not smooth, the power is insufficient, and the fuel consumption of the vehicle will naturally increase.

If driving on a normal city road, the air filter should be checked when the car is driving 5000 kilometers, and if there is too much dust on the filter, you can consider blowing compressed air from the inside of the filter to the outside to blow the dust away.

2.Repels throttle sludge.

There are many reasons for the formation of sludge at the throttle, some of which are the formation of carbon deposits at the throttle by the exhaust gas of fuel combustion; Then there are the impurities that are not filtered by the air filter and remain at the throttle. The increase in oil sludge will cause air resistance, which will lead to an increase in fuel consumption.