03 Mar

What is a muffler in a car

In this article, we will consider the topic of a muffler in a car, the purpose and device, for sure, all drivers understand that the recipe for quiet or silent engine operation lies precisely in the quality and method of implementing a muffler in a car. But how it all works and what, more additional functions performs a car muffler we will talk below.

Silencer in a car device and purpose

What is the main function of the muffler - it removes the spent traffic fumes from the car engine and at the same time reduces the sound of the engine and the sound of the exit exhaust gases, by converting sound energy into heat.

Vehicle muffler device

The device of all mufflers is approximately similar and includes the required elements:

• Expansion and contraction of the flow of outgoing gases, the so-called throttling, due to which both the speed of the outgoing gases and the frequency of sound waves change
• The superposition of sound waves on each other, due to which their amplitude changes - interference
• Absorption and dispersion of sound waves - there is a conversion of sound energy into heat, due to which there is a very significant reduction in the sound of the outgoing exhaust
• Reusable change in the flow of outgoing gases, the so-called labyrinth, also serves to reduce the rate of gas exit, its energy and conversion into thermal energy

Cutaway muffler

Let's see the car muffler device in section in this photo,

Here we see that the elements of the muffler are obligatory, or, so to speak, what the muffler of the car consists of:

1. Exhaust manifold (popularly called pants or spider for similarity in design)
   
2. Flame suppressor or resonator
   
3. Connecting pipes between silencer chambers
   
4. Silencer main frame
   
5. And the exhaust pipe itself.
   

• The exhaust manifold is pipes that are directly attached to the engine outlets to actively take exhaust gases directly from the car's cylinders, so temperatures at the junction of the manifold and the engine can reach values ​​​​of 1000 degrees Celsius
• Therefore, the requirement for the exhaust manifold is always high - it is the obligatory thermal stability of the material and strength in relation to mechanical loads, which is why the manifold is often made of cast iron or heat-resistant steel.
• The muffler resonator, as a rule, is a pipe with holes drilled in it of different diameters, which is located in a closed chamber due to the expansion and release of gases through the holes of this pipe and their resonation occurs, in fact, the damping of oscillations and changes oscillatory circuit sound wave
• The main muffler is essentially like a multi-room apartment, only the rooms are connected there not by doors and hollow pipes, and sometimes, in order to get into another room, exhaust gases have to pass through pipes from other rooms back and forth several times - this is done to extinguish the energy of the gas and convert it into heat energy, due to this energy conversion, the sound wave is reduced

Well, I think that we answered the question of a muffler in a car, the purpose and device, and now you have at least an idea about its device.

Car muffler repair

As a rule, a Hyundai Santa Fe or any other car boils down to welding rotten holes in the main muffler; as a rule, only fierce enthusiasts undertake to digest the internal parts. Yes, and there is no point in overcooking the entrails on the old muffler as such. Because the metal is already tired of sound and temperatures and has become loose and rotten, so to speak, so it’s easier to buy a new muffler. But, and there everyone looks, of course, according to their financial capabilities and the mood of the soul.

Here is another photo of a car muffler diagram, so to speak, for completeness of understanding, two types of muffler are clearly visible here, a regular muffler and a straight-through muffler, as you understand, in a straight-through muffler, due to its device, the sound will be much louder, since it does not have damping chambers for sound

Do-it-yourself car muffler soundproofing

There is no consensus among drivers in the sound insulation of the muffler, and this is understandable, here, as they say, a double-edged sword, on the one hand, the sound insulation of the muffler will reduce the level of noise fluctuations, but on the other hand, it will create overheating of all parts of the muffler.

Basically, silencer soundproofing materials are used, such as asbestos fabric, or more modern heat-resistant and vibration-resistant materials.

Soundproofing itself usually comes down to wrapping all parts of the muffler with this heat-resistant and sound-absorbing material.

Some craftsmen even wrap the exhaust manifold of a car muffler, which also raises a lot of questions, both about overheating of the manifold itself and the difficulty in cooling part of the engine at the junction exhaust manifold with engine. Here it is worth weighing the pros and cons of such a procedure. But the fact that there will be a large overheating of the entire muffler due to its winding noise with insulating materials is one hundred percent.

How to paint a car muffler

Sometimes some car owners wonder how to paint a car muffler, this is usually due to two reasons.

1. The desire to hide the rust on the muffler
2. Give a beautiful stylish look to the car

In any case, the paint for this type of work will be very expensive, since the main requirement for such a paint will be great heat resistance and the ability to withstand large temperature changes,
and even when buying such paint, if it is used in the area of ​​\u200b\u200bthe collector where the temperature is 1000 degrees Celsius, then it is unlikely that if it resists, it will not change its color from such high temperatures. Therefore, the very idea of ​​\u200b\u200bpainting the muffler has a place to be, but as they say, at your discretion.

A car is made up of many parts. From stable operation each of them depends on performance, dynamics, power, safety. The failure of one part can lead to serious consequences up to an accident.

Of course, every driver knows that the heart of the car is the engine. But his work would not have been possible without the quality exhaust system. To understand its importance, let's draw a parallel with biology. You know that thanks to the lungs, the respiratory processes in the body are supported. They are also responsible for removing carbon dioxide from the blood. If this does not happen, then oxygen starvation begins.

Of course, nothing good disadvantage cannot bring oxygen to the blood. In the worst case, brain function is disrupted, which, in turn, can lead to death. In the event of a malfunction of the exhaust system of a car, everything is not so tragic. But loss of power and increased fuel consumption are guaranteed. That is why it is important to understand how this unit works in order to carry out repairs if necessary.

Attention! In the worst case scenario, a malfunction of the car's exhaust system can lead to the ingress of exhaust gases into the passenger compartment.

An important function of the exhaust system of a car is to reduce engine noise. Also not to be ignored are important features, as improving the performance of internal combustion engines and cleaning exhaust gases before being released into the atmosphere.

History of creation

The first engine models internal combustion created a deafening roar. In addition, they were very low-powered and allowed cars to reach extremely low speeds compared to modern supercars.

To slightly increase the power, the automakers of that time created the exhaust systems of a car in such a way that the exhaust gases entered the atmosphere immediately through a special valve. This device was a primitive analogue of a silencer, the installation of which had a positive effect on power and efficiency.

The driver himself had to open the valve of the exhaust system so that the exhaust gases would come out. At the same time, a deafening whistle was heard, frightening everyone around. This action was also accompanied black puffs of smoke.

Attention! The operation of the exhaust system valve was so terrible that drivers were forbidden to open it within cities.

Due too hands-free work exhaust system, there was a kind of confrontation between the townspeople and drivers. As a result, the governments of all countries have issued a law prohibiting the opening of the valve within the city.

Naturally, resourceful automakers could not miss such a chance to get ahead of their competitors. The development of a quieter exhaust system for cars began to gain momentum.

The first silencer prototype was created by the pioneers automotive industry by The Reeves Pulley Co. The author of the same invention is Milton Reeves. It happened in 1896. scientist created partition system, which was designed to minimize the noise generated by the internal combustion engine.

Of course, for more than 100 years, the muffler for the exhaust system of a car has gone through many upgrades. One of the main ones was carried out by the French engineer Eugene Goodry. It happened not so long ago. In 1962, the scientist filed a patent for a catalytic silencer. This structure is the basis for modern device responsible for noise reduction.

The basic structure remained unchanged. All the same partitions greatly reduced the sound of the engine. But now they were used to create Additional materials, increasing the efficiency of the entire exhaust system. Moreover, all these elements were placed in closed systems.

Attention! Modern mufflers have a similar design, with one exception. Now most manufacturers use fiberglass as an absorbent material.

If we talk about the general structure of the exhaust system of a car, then over the past 50 years it has not changed much. Small improvements were made in the early 2000s, but they also concerned the muffler. Variable flow designs emerged. This made it possible to moderate the noise of the internal combustion engine for a different number of revolutions.

Also interesting innovations include electronic silencers. They serve to make the noise lower, using special headphones for this purpose. This modification allowed the design to take another small technological step into the future.

How does a car exhaust system work?

Device

To understand how the exhaust system of a car works, you need to take a closer look at its structure. The design itself is closely related to the functioning of the mechanism responsible for the distribution of gas. The mechanism itself consists of exhaust valves and a manifold.

The composition of the exhaust system of a car includes the following structural elements:

• intake pipe,
• resonator,
• catalyst,
• muffler,
• sensors or lambda probe.

Also, do not forget about particulate filter, which makes the exhaust system for cars safer for the environment. This is the canonical scheme of the exhaust system of a car. Naturally, manufacturers can contribute to the design additional elements and modifications to achieve greater performance.

Attention! In detail, the main device of the exhaust system of a car, you can see in the diagram below.

The car exhaust pipe is a curved design with a welded sole. It connects to the exhaust manifold. In some modifications, a connection with a turbocharger can be observed.

The material of the exhaust pipe of the car exhaust system is fire-resistant metal. Although sometimes manufacturers can use stainless steel, but similar cases are quite rare. Vehicles with increased power have multiple pipes.

The resonator is shaped like a jar. It is in it that the exhaust gases are separated. Also, this element significantly reduces the speed of the exhaust. The material of manufacture is refractory steel.

The catalyst cleans the exhaust gases. By appearance the device resembles a metal container. The inner layer is fireproof. The main structural element is the body. It, in turn, is divided into ceramic and metal.

The ceramic catalyst consists of three components that help neutralize the exhaust:

1. The first element is a simple wire mesh. It is usually made from of stainless steel.
2. The mesh covers the ceramic cushion, which is also the second element. Its constituent elements are aluminum silicate and mica.
3. Thermal insulation completes the design of the catalyst. In fact, this is a simple case, which is characterized by high heat resistance and has double walls.

The metal catalyst of the car exhaust system is coated with a layer of palladium or platinum. The basis is corrugated foil. In all other elements, the design is similar to the ceramic counterpart.

The lambda probe is installed on threaded connection. His the main task is to fix the amount of oxygen in the exhaust gases and transmit information to the control unit. Based on it, certain adjustments are made. ICE operation.

The muffler is a simple metal container. Partitions are placed inside and special materials, contributing to the reduction of noise during the operation of the car engine. The main task of the device is to moderate the flow of exhaust gases.

All elements of the design of the exhaust system of a car work with each other in close cooperation. The failure of one element leads to the fact that the entire system begins to fail. That is why automotive manufacturers spend a lot of time and money to create a truly reliable structure.

Principle of operation

The principle of operation of the exhaust system of a car is not particularly complicated. Moreover, it has not changed much since the introduction of this structural element into the car.

The exhaust system of the car still works thanks to exhaust valve. When this mechanism opens, the exhaust gases enter the exhaust manifold. Then it all depends on ICE type.

If the car has Gas engine, then the exhaust system sends gases through the exhaust pipe. IN diesel internal combustion engines everything happens a little differently. The exhaust gaseous substances cause the impeller to rotate. Naturally, this greatly increases Device efficiency.

Attention! In diesel internal combustion engines, exhaust gases enter the exhaust pipe only after the turbocharger impeller is forced to work.

From the exhaust pipe of the car, gaseous substances are redirected to the catalyst. There is a settling of harmful impurities. More precisely, active elements . The structural element itself is able to work normally only at temperatures of 250 degrees and above.

Behind chemical composition gas responds lambda probe. Ideally, the exhaust system of a car has two sensors at once. One is at the inlet to the catalyst, and the other is at the outlet. This allows you to ensure high productivity of the system.

The main advantage of systems with two sensors is a more accurate display of data. This structure allows you to more accurately fix the ratio of air and fuel.

After the lambda probe collects information, it sends it to the control unit. Based on the received data, commands are issued for the injection system. fuel mixture into the engine cylinders. More precisely, there is an adjustment of the ratio of air and fuel.

As soon as the exhaust gases pass through the catalyst, the exhaust is “quenched”. Eventually gaseous substance, which entered the muffler, poses a much lesser danger to the environment.

Attention! The mufflers change the direction of the exhaust. Because of this, the noise is drastically reduced.

After passing through all the elements of the car exhaust system, the exhaust gases escape into the atmosphere. In many ways, the efficiency of this unit depends on the thickness of the pipes, which also represent an important part of the mechanism. Moreover, the catalyst and muffler must be clean enough. Otherwise, the exhaust may be difficult.

If the catalyst and muffler are clogged, then the exhaust gases will accumulate in the car's cylinders. It is because of this that in most cases the power of the motor drops. In the most difficult cases, this leads to the fact that the entire fuel system falls into disrepair.

Results

The exhaust system plays a huge role in the operation of the car. If it malfunctions, there is a serious drop in power and increased consumption fuel. If timely measures are not taken, then this automotive unit may fail and cause damage to all other units.

Silencer is one of essential elements exhaust system. Exploitation modern car without a muffler is simply impossible. Car muffler functions:

1. reduction of noise of the fulfilled gases;

2. transformation of the exhaust gases themselves, that is, a decrease in their speed, temperature (t), pulsation.

It is worth remembering the pressure of the exhaust gases, it is very high. When moving gases that have already worked out through the exhaust system, a certain sound can be created that can spread more actively than gases. A car muffler reduces sound vibrations by converting them into heat energy. In addition, with the use of a silencer, a certain back pressure is formed in the exhaust system, which ultimately leads to a certain decrease in engine power.

What technologies in the muffler reduce noise?

Expansion (narrowing) of the flow, which allows you to reduce sound vibrations;

Change of flow direction. The angle of rotation of the air flow is in the region of 80-350 °, which dampens medium and large sounds.

A change in sound waves, which, depending on the nature of their superposition, can lead to a change in states - an increase (constructive interference) or a decrease (destructive interference) of the oscillation amplitude. There are 2 types of changes applied to the muffler. The technology works with the help of special perforations in the silencer pipes themselves for a foreign car or a VAZ car. By changing the size of the holes and the volume (V) of the chamber surrounding the pipe, it is possible to obtain a reduction in sounds in a significant frequency range.

Absorption of sound waves. This method suitable for reducing high-frequency sound vibrations.

Two types of sound changes are often used.

In produced cars, from 1 to 5 mufflers are used, but most often - two. The muffler close to the engine is called the pre-muffler or front muffler or resonator. Then comes the rear (main) muffler. As a rule, for each specific model cars and engine brands use certain mufflers.

How is the resonator

The resonator serves to preliminarily reduce sound vibrations and the flow of exhaust gases. The resonator is a perforated pipe in a metal case. In order to effectively reduce fluctuations in the pipe, a throttle orifice is used.

Main silencer device

The main muffler significantly "extinguishes" the noise. It has a more complex structure. A small number of perforated tubes are located in the metal case. The body is divided by partitions into several chambers. Some of these chambers can be filled with special sound-absorbing material. In the main muffler, the flow of gases that have already changed their direction many times is a labyrinth muffler.

Drivers who want to improve, tune the exhaust system most of all pay attention to the muffler. When tuning the exhaust system, the so-called. straight-through silencer (one straight-through pipe for all chambers without changing the flow direction). Such a muffler has a reduced back pressure, but it does not give a significant increase in engine power. The main plus of a straight-through muffler is the “noble” or “sporty” sound of your car (whoever likes it more).

Direct-flow muffler device

The structure of the straight-through muffler is connected by a stainless steel body, in which a special perforated pipe is located, which is wrapped with a steel mesh and a special sound-absorbing material. The steel mesh protects the sound-absorbing material from being blown out. A simple glass fiber is used as a sound-absorbing material. IN straight-through muffler sound waves pass without problems through the holes of the pipe, the metal mesh and are absorbed by the fiberglass (converted into simple thermal energy).

In order to deal with the sound of a shot, it would be logical to understand what is the source of the sound when fired. There are several such sources:

1) The sound of the mechanism of the weapon, the impact of the striker on the primer, the clang of the shutter, etc. On a quiet night in an open area, the sound of a blow metal parts AK mechanism is clearly audible at a distance of up to 50m. That is why, when one absolutely silent shot is required, single-shot weapons are used.

2) The sound created by the air in the barrel before the shot, and displaced by the bullet and powder gases; sound created by expanding (from a pressure of about 200 kg / cm 2 to the usual atmospheric 1.9 kg / cm 2) and cooling (from hundreds of degrees to air temperature) powder gases at the time of exit from the barrel, and these gases mostly follow the bullet , but some of them still break through into the gap between the barrel and the bullet, and, therefore, ahead of the bullet. It is with this cause of sound that the silencer allows you to fight.

3) Acoustic shock wave that forms behind a bullet if it exceeds the speed of sound (~330m/s). It arises due to the fact that a bullet, passing through the air, creates waves in it, similar to those that arise on the water when a boat floats; the loudness of these waves is not great if they move faster than a bullet; however, if the bullet moves faster, it seems to accumulate the energy of the wave following it, and therefore it is perceived by the human ear as a blow, something like thunder during a thunderstorm. The only way to get rid of this cause of the sound is to reduce the speed of the bullet, which can be achieved by using special cartridges with a smaller charge of gunpowder or by shortening the barrel of the weapon.

4) The sound of a bullet hitting a target.

Now that we know the reasons for the sound of a shot, we can consider the principle of the silencer. The main task of the muffler is to reduce the pressure and temperature of the powder gases. In order to reduce the pressure, it is necessary that the gases have the opportunity to expand before contact with atmospheric air. This is the purpose of the silencer chambers. The powder gases that escaped from the barrel after it consistently lose energy in each such expansion-cooling chamber. It is clear that with an increase in the number of chambers, the pressure difference between the outgoing gas and the outside air becomes smaller and, accordingly, the sound is attenuated. However, these reasonings are correct only for gases following the bullet. And as it was said, part of the gases is ahead of it. Since the diameter of the bullet holes in the baffles is larger than its own diameter, this part still flows out of the silencer at supersonic speed, creating a ballistic shock wave. To cut off and slow down supersonic gases, instead of diaphragms with holes, for example, membranes made of an elastic material with slots are used, which let the bullet through and close again, or put blind gaskets - obturators.

Protozoa homemade muffler- regular plastic bottle, taped to the barrel with electrical tape. At the moment of the shot, all the powder gases will be in the bottle, and the bullet, having broken through the bottom, will fly out. Despite the bulkiness and decrease in shooting accuracy, such a silencer makes the sound of a shot with a small-caliber cartridge no louder than a crack from a broken plastic ruler.

There are many different muffler designs that use different tricks to reduce the temperature and pressure of propellant gases. For example, the legendary "Bramit" in the version for the "three-ruler" was a cylinder with a diameter of 32 mm and a length of 140 mm, inside divided into two chambers, each of which ends with an obturator - a cylindrical gasket made of soft rubber 15 mm thick. The cutter is placed in the first chamber. Two holes about 1 mm in diameter were drilled in the walls of the chambers for bleed-off of powder gases. When fired, the bullet pierces both obturators in turn and exits the device. Powder gases, expanding in the first chamber, lose pressure and slowly bleed out through the side holes. Part of the powder gases, which broke through the first obturator together with the bullet, expands in the same way in the second chamber. As a result, the sound of the shot is extinguished. A similar silencer with a large number of chambers was also developed for the Nagan revolver of the 1895 model.

A fairly typical example of a modern silencer is the domestic PBS, that is, the Silent Shooting Device, which is screwed onto the muzzle of the barrel of AKM or AK-47 assault rifles. At some distance in front of the barrel is a thick rubber washer. Leading gases are retained by it and through special channels are sent to the expansion chamber, from where they flow smoothly into the air. When the bullet pierces the puck, most of the gases follow it; but, having successively passed through several expansion chambers, these gases escape into the atmosphere, having lost a significant part of the energy. PBS reduces the volume by 20 times. Therefore, a shot from an AKM is practically inaudible already at a distance of 200 m. The survivability of a PBS without changing the puck is up to 200 shots, which is quite acceptable for a special weapon. The disadvantage of this design is the aging of rubber, and after all, spare plugs also age - even without being used in a muffler. Currently, there are literally innumerable options for multi-camera devices. Here is the device of one of the foreign silencers for a Kalashnikov assault rifle -

But along with an increase in the number of cameras and the complexity of their configuration, the improvement of designs is the most different ways. The bulky body of the silencer often covers conventional sights, so it is placed eccentrically - the axis of the device is much lower than the axis of the barrel. But, of course, the channel for the passage of a bullet must be strictly coaxial with the barrel, because even with its light touch on the internal partitions, the accuracy of fire is sharply reduced. And the weakening of the attachment point of the device body on the weapon can generally lead to firing through its front wall ...

The flat partitions of the expansion chambers are often replaced with convex ones - cone-shaped or of another shape, which deflect the flow of powder gases to the peripheral part of the muffler, which prevents it from overtaking the bullet. The same effect is generated by a helical baffle that runs along the entire length of the device.

Sometimes the expansion chambers are partially filled with heat-absorbing material - a fine aluminum mesh or just shavings, copper wire. By heating them, the gases are cooled more actively. But these fillers are difficult to clean from powder deposits, and they have to be changed periodically. The damping efficiency is also affected by the material of the baffles themselves: for example, replacing steel with aluminum, more thermally conductive, results in a noticeable decrease in volume. However, with frequent firing with such a silencer, as the pressure in the chambers increases and the heat sink heats up, the device's performance decreases sharply; if a dozen or two shots are fired from it in a row, the "silent" weapon turns into the most common one. Therefore, it is recommended to fire with single shots and with long pauses to allow the entire structure to cool.

Sometimes, to improve the performance of the muffler, it is pre-moistened with water. Just a tablespoon is enough. At the same time, the muffler is cooled due to the evaporation of water (the principle of operation of freon in a refrigerator). Also, adding water to the muffler slightly changes the sound of the shot, from a metallic "melon" to a more deaf "tan". Water is usually enough for 10-20 shots.

Silencer efficiency is also increased by complex and rigorous internal gas dynamics calculations. For example, due to the use of shaped partitions of a certain profile, countercurrents and turbulent gas eddies are created in the chambers. As a result, its molecules, repeatedly colliding in different directions, extinguish each other's energy.

Original designs have been developed that provide for the reflection of the gas flow from the inner surface of the front wall of the muffler. After that, the energy of the gases drops due to repeated reflection and counter damping of shock waves inside the housing. Such devices can also be multi-chamber.

A completely exotic device has also been invented, outwardly looking ridiculously primitive: just a muzzle cone-diffuser enclosed in a tube with open ends. But a very significant reduction in sound is provided here by a virtuoso calculation of the interference of shock waves inside the cone, and most importantly, by a surprisingly ingenious way of cooling the powder gases. Breaking out of the cone, they intensively eject outside air, as if instantly sucking it out of the internal volume of the tube, which is why its pressure and temperature drop sharply. And the gases, mixing with this rarefied cold air, immediately lose energy. So, probably, a shot would have sounded somewhere at a twenty-kilometer height ...

The simplest muzzle silencer 1 - rubber membrane with a slot 2 - expansion chamber 3 - connecting nut	Silencer with reflector reflector 1 - parabolic reflector 2 - body 3 - nut 4 - trunk
Multi-chamber silencer 1 - camera 2 - partition	Double chamber eccentric muffler 1 - camera 2 - partition
Silencer with preliminary removal of powder gases from the bore 1 - hole in the barrel with a reverse channel 2 - front multi-chamber part of the muffler 3 - expansion rear camera	Silencer with obturation 1 - spacer sleeve 2 - rubber (ebonite) obturator 3 - expansion chamber
Multi-chamber muffler with heat-absorbing filler 1 - nut 2 - wire mesh

The car should not only drive well, but also sound great. Good car beautiful in all respects and beauty is partly dependent on the sounds that the technique makes. Spectacular sound closed door, with a noble low overtone, a muffled clatter of the turn relay, a dense rustle of a headwind at a speed of 180 km / h. And, of course, the sound of the exhaust. It is the muffler that forms the first impression about the car and we will talk about the muffler today.

Tasks of a car muffler

Pipe. Exhaust, but pipe. The simplest device at first glance, but a lot depends on the exhaust system. Not only the aesthetic sound of the exhaust, but also the dynamics of the car, and fuel consumption, and comfort in the cabin, and the presence of vibrations. Therefore, if someone asks in the middle of the night why a muffler is needed in a car, every self-respecting motorist will answer without hesitation:

• to reduce the noise level of the engine;
• to reduce the temperature of the exhaust gases;
• for the removal of exhaust gases outside the car;
• to reduce the level harmful emissions in atmosphere.

Although the last point is rather conditional.

The exhaust pipe works in hellish conditions. The temperature of the exhaust gases at the outlet of the exhaust manifold can reach 800 degrees, or even more. Therefore, the metal from which the muffler is made must not only be durable, but also have some heat-resistant qualities. In addition to temperature, the walls of the exhaust system are affected by huge pressure, A high speed the movement of the exhaust gases causes significant sound vibrations.

How to reduce exhaust noise

The sound wave is able to move in space much faster than gases, therefore, in the design of the silencer, its noise reduction circuit is of great importance. Physical vibrations from sound waves are transmitted to the walls of the exhaust system, and its design is made in such a way that it converts the sound wave into thermal energy, which the exhaust pipe, like a radiator, gives off to the atmosphere.

Reducing the noise level of the muffler cannot be achieved without creating some resistance to the exhaust gases, as a result of which a part of the engine power, rather insignificant, is spent on overcoming this resistance. To minimize the power loss that noise reduction inevitably leads to, a straight-through muffler has been developed.

It has a minimum of baffles, does not oppose the passage of exhaust gases and reduce their speed so much, and therefore it sounds completely different.

Sound Absorption Technologies

Car muffler diagrams

The device of the car muffler in the section allows you to trace exactly how the sound suppression function is implemented in each specific muffler. Direct-flow, for example, never use the method of changing the direction of the movement of gases, and the standard muffler uses turns from 90 to 360 degrees. The change in the amplitude of the sound wave oscillations is implemented by perforating the inner tubes. It is these inner pipes, their diameter, diameter and frequency of the holes, that can drown out the noise in almost the entire frequency spectrum.

The muffler resonator is installed immediately after the exhaust pipe and the catalyst, and its task is to level the pulsations of the gas flow. In section, it looks like a perforated pipe placed inside a metal chamber of a larger diameter. The pipe can change the section on the way from the inlet to the outlet of gases.

The main muffler may have a more complex design and it is the main function of noise reduction. Modern systems can have almost all noise reduction schemes in the device of the rear muffler bank. The chamber through which the main pipe passes can have several sections, each of which has noise reduction at its own level. As a rule, these chambers are filled with heat-resistant fibrous material, which further dampens vibrations and absorbs sound vibrations.

The design of a car muffler is constantly evolving, and we try to follow the news from the design bureaus of the most progressive automakers and tuning studios. Stay with us and let your mufflers only caress the ears of avid motorists. Good luck to all the roads!