RU2056508C1 - Internal combustion engine silencer - Google Patents

Abstract

FIELD: internal combustion engines for exhaust noise suppression. SUBSTANCE: silencer has housing mounted vertically and provided with intake and exhaust branch pipes, and transverse perforated partitions; branch pipes are partially located in housing and their internal parts are perforated; ends of branch pipes are blanked off and are secured on partitions forming the intake, intermediate and exhaust chambers. Diameters of holes are reduced in way of motion of gas flow and their number are related by definite relationship; diameter of holes and area of passage sections of perforated partitions are related with diameter of intake branch pipe. Relationships at coefficients of 1.272, 1.618 and 2.618 ensure similar throughput of partitions. EFFECT: enhanced efficiency of noise suppression. 1 dwg

Description

 The invention relates to engine building and can be used in the exhaust system of internal combustion engines.

Known silencer for an internal combustion engine, consisting of an oval body, transverse, partially perforated partitions, a coaxial perforated resonator with swirls and a conical nozzle, while the resonator is made in the form of two coaxial pipes fixed in transverse partitions [1]
However, the performance of such a silencer is low for the reason that the parameters of the perforation of the coaxial pipes and transverse partitions are not interconnected with the dimensions of the inlet pipe, certain ratios.

Also known is a silencer for an internal combustion engine, comprising a housing with coaxial inlet and outlet nozzles and transverse perforated partitions, the inlet and outlet nozzles being partially located in the housing and perforated, and their ends mating with transverse partitions [2]
The efficiency of such a device is somewhat increased due to a more complete perforation of the transverse partitions, however, in general, there is also a low degree of noise suppression because the perforation parameters of the inlet, outlet pipes and transverse partitions are not related to each other and to the dimensions of the inlet pipe by certain ratios .

где прямые скобки обозначают целую часть числа;
Z количество отверстий перфорации;
2,618 коэффициент пропорциональности [3]
Эффективность шумоглушения такой конструкции повышается за счет достижения одинаковой пропускной способности перфорации поперечных перегородок. Однако параметры перфорации перегородок здесь не связаны с диаметром впускного патрубка определенными соотношениями. Это не позволяет достаточно точно рассчитать параметры перфорации внутренних элементов и получить, тем самым, наибольшую эффективность шумоглушения.The closest in technical essence and the achieved positive result to the invention is a silencer of the internal combustion engine comprising a cylindrical body with coaxial inlet and outlet pipes, and at least two transverse perforated partitions dividing the body into expansion chambers, and the partitions are made with the diameter of the perforation holes decreasing, and the number of holes increasing towards the exhaust pipe, while the diameters of the holes of the perforation of the partitions are related by
d _n = 1,618 · d _{n + 1} , where d is the diameter of the perforation hole;
n serial number of the partition, counting from the inlet;
1,618 coefficient of proportionality, and the number of perforation holes of the partitions is determined by the dependence
Z _n =

where the brackets denote the integer part of the number;
Z number of perforation holes;
2.618 proportionality coefficient [3]
The sound attenuation efficiency of this design is increased by achieving the same perforation throughput of the transverse partitions. However, the perforation parameters of the partitions here are not related to the diameter of the inlet pipe by certain ratios. This does not allow to accurately calculate the parameters of the perforation of the internal elements and thereby obtain the highest noise attenuation efficiency.

 An object of the invention is to increase the efficiency of sound attenuation.

(2) где d₁ диаметр отверстий перфорации впускного патрубка;
Z₁ количество отверстий перфорации впускного патрубка;
1,272 коэффициент пропорциональности.This goal is achieved by the fact that in the proposed silencer of the internal combustion engine the inlet and outlet pipes are partially located in the housing, made perforated and their ends are respectively mated with transverse partitions, while the area of the passage sections of the perforation of the pipes is equal to the area of the passage sections of the perforation of the partitions and its value is determined according to the formula
F1 = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ , (1) where F _{1 is the} area of the inlet section of the perforation of the inlet pipe;
d _vp the diameter of the inlet pipe, while the diameter of the holes of the perforation of the inlet pipe is determined by the equation
d ₁ = d _vp •

(2) where d _{1 is the} diameter of the holes of the perforation of the inlet pipe;
Z _{1 the} number of holes in the perforation of the inlet pipe;
1.272 coefficient of proportionality.

 Partial placement of the nozzles in the housing, making them perforated and matching their ends with transverse partitions, respectively, allows to increase the degree of perforation of the internal elements of the silencer, starting from the gas inlet to the housing, and at the same time to change the direction of gas flow at the inlet and outlet and thereby increase the noise reduction efficiency . It is advisable to use such a design scheme in noise suppressors for diesel engines, since in them, as a rule, there is a change in the direction of the exhaust gas flow simultaneously with its crushing into smaller jets.

 The equality of the areas of the passage sections of the perforations of the inlet and outlet pipes and the transverse partitions between them allows one to obtain the same throughput of all internal perforated elements and stabilize the movement of exhaust gases, and therefore, increase the efficiency of noise damping.

 Determination of the area of the inlet perforation inlet pipe, and therefore of all other perforated elements, by the formula (1) allows you to adjust its size depending on the cross-sectional area of the inlet pipe, and, therefore, the volume of the engine cylinders, which also leads to a stable gas flow flow through all internal perforated silencer elements and increase work efficiency.

 Determining the size of the diameter of the inlet perforation holes by the formula (2) allows you to get the same area of the bore sections of the internal elements depending on the diameter of the inlet pipe, which also determines the stable movement of the gas stream at the inlet and outlet and increase the noise reduction efficiency.

 If the cross-sectional area of the perforation of all internal elements is not the same but different, for example, the cross-sectional area of the inlet pipe is larger or smaller than the other elements, then in this case there will be a violation of the stabilization of the gas flow due to a change in the local aerodynamic drag. Therefore, the silencer’s performance will decrease.

Take F <d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ not constructive, since the perforation cross-section should be larger than the cross-sectional area of the inlet pipe taking into account local resistance losses, uneven flow of the gas stream, its pulsating nature, soot deposition. This complicates the formula (1) and the calculation method of silencers.

Take F ₁ > d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ it is impractical for the reason that in this case the dimensions of the internal elements of the structure and the housing as a whole will be overestimated and, again, formula (1) and the calculation method of the silencers are complicated.

 Only strict observance of all the distinguishing features (in its entirety of the indicated relationship) allows to obtain high efficiency of damping the noise of the exhaust.

 The invention is illustrated in the drawing.

 The noise suppressor comprises a housing 1 mounted vertically with coaxial inlet 2 and exhaust 3 nozzles, transverse perforated partitions 4 and 5, the nozzles 2 and 3 partially housed in the housing and their internal parts perforated, while the ends of the nozzles are muffled and mated respectively to the transverse partitions 4 and 5 with the formation of the inlet chamber 6, the intermediate chamber 7 and the exhaust chamber 8. Perforation on the inner parts of the nozzles 2 and 3 and on the transverse partitions 4 and 5 is made in the form of round holes, when volume along the gas flow, the diameters of the holes are reduced, and their number is increased.

The area of the flow sections of the perforation of the nozzles 2 and 3 and the partitions 4 and 5 is made the same and is determined by the formula
F ₁ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ where F _{1 the} area of the orifice perforation of the inlet pipe 2;
d _vp diameter of the inlet pipe.

The diameters of the holes of the perforation of the partitions is determined by the formula
d _n = 1,618 · d _{n + 1} , where n is the serial number of the perforated septum, counting from the inlet pipe 2;
d _{n the} diameter of the holes of the perforation of the n-th partition;
1,618 coefficient of proportionality.

где прямые скобки обозначают целую часть числа;
Z_n количество отверстий перфорации n-ой перегородки;
2,618 коэффициент пропорциональности.The number of perforation holes for partitions is determined by the formula
Z _n =

where the brackets denote the integer part of the number;
Z _{n the} number of perforation holes of the n-th partition;
2.618 coefficient of proportionality.

где d₁ диаметр отверстий перфорации впускного патрубка;
Z₁ количество отверстий перфорации впускного патрубка;
1,272 коэффициент пропорциональности.The diameter of the inlet perforation holes is determined by the formula
d ₁ = d _vp •

where d _{1 the} diameter of the holes of the perforation of the inlet pipe;
Z _{1 the} number of holes in the perforation of the inlet pipe;
1.272 coefficient of proportionality.

 The number of inlet perforation holes is taken to be equal to one of the numbers of the Fibonacci series, starting, for example, from 13 or 21, or 34, etc.

 The muffler works as follows.

 The exhaust gases through the perforation openings of the inlet pipe 2 enter the inlet chamber 6, and then through the perforated baffle 4 into the intermediate chamber 7. In the chamber 7, the static pressure of the gas flow is equalized (by reducing the dynamic pressure) and its increase, which then is spent on overcoming subsequent aerodynamic drag during the passage of gases through the perforation of the partition 5.

 From the chamber 7, the exhaust gases through the perforated baffle 5 pass into the exhaust chamber 8 and then through the perforated section of the exhaust pipe 3 are released into the environment. Since the area of the perforation cross sections of the inlet pipe 2, the baffle 4, the baffle 5, and the outlet pipe 3 are equal, this circumstance ensures a stable flow of the gas stream, a gradual decrease in its velocity and a decrease in the noise level. At the same time, there is a change in the direction of gas movement and a gradual fragmentation of the gas stream into increasingly smaller jets, so the diameters of the openings in the direction of exhaust gases decrease, and their number increases. It also contributes to the gradual, smooth braking of the gas flow and lower noise levels, which is especially important for diesel engines.

 The cross-sectional area of the perforation of the internal elements, determined by the formula (1), is larger than the cross-sectional area of the inlet pipe. This is done in order to partially compensate for additional local resistances when the gas flow moves through the perforations of the inlet pipe 2, partitions 4 and 5 and the outlet pipe 3, by increasing the area of the flow cross sections, especially since not all perforation openings work with the same efficiency.

This helps to stabilize the movement of the gas stream and increases the efficiency of the device. This positive effect is further enhanced by the fact that the perforations on all internal elements of the silencer are made in the form of round holes, which also stabilizes the movement of exhaust gases,
Using formulas (1) and (2) to calculate the perforation parameters of the inlet pipe 2 allows you to determine its value depending on the diameter of the inlet pipe, and therefore, on the volume of the cylinders of the internal combustion engine.

 And now it is necessary to give explanations to the formula (1). This formula is obtained on the basis of the following reasoning.

The area of the inlet perforation of the inlet pipe, and therefore of all other internal elements, should be slightly larger than the cross-sectional area of the inlet pipe. Given the deposits of soot, the uneven performance of the perforation holes, the uneven flow of the gas stream in its cross section, the presence of turns, pulsations, etc., it is advisable to take the perforation area of the inlet pipe more than its cross-sectional area, namely:
F ₁ = 1.272 · f _vp where F _{1 the} area of the passage through the perforation of the inlet pipe;
f _vp cross-sectional area of the inlet pipe;
1.272 coefficient of proportionality.

где d_в.п. диаметр впускного патрубка, зависит от литровой мощности двигателя внутреннего сгорания.F ₁ = 1.272 •

where d _vp the diameter of the inlet pipe depends on the liter capacity of the internal combustion engine.

. где Φ1,618 значение золотой пропорции (см. Васютинский Н. А.On the other hand, 1,272 =

. where Φ1.618 is the value of the golden ratio (see N. Vasyutinsky

 Golden proportion. M. Young Guard, 1990.238 s.).

Тогда получается
F₁= 1,272•f_в.п= 1,272•

•d $\genfrac{}{}{0ex}{}{\text{2}}{\text{в.п}}$ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{в.п}}$ , т.е. F₁= d $\genfrac{}{}{0ex}{}{\text{2}}{\text{в.п}}$
С другой стороны
F₁=

• Z₁ где d₁ диаметр отверстий перфорации впускного патрубка;
z₁ количество отверстий перфорации впускного патрубка.At the same time, the relationship between the golden ratio and the number π is known

Then it turns out
F ₁ = 1.272 • f _vp = 1.272 •

• d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ , i.e. F ₁ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$
On the other hand
F ₁ =

• Z ₁ where d _{1 is the} diameter of the holes of the perforation of the inlet pipe;
z ₁ number of inlet perforation holes.

• Z₁= d $\genfrac{}{}{0ex}{}{\text{2}}{\text{в.п}}$ ; d $\genfrac{}{}{0ex}{}{\text{2}}{\text{т}}$ d $\genfrac{}{}{0ex}{}{\text{2}}{\text{в.п}}$ •

Окончательно имеем
d₁= d_в.п•

Во всех формулах коэффициенты пропорциональности связаны между собой определенной зависимостью через значение золотой пропорции Φ
т. е.Or

• Z ₁ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ ; d $\genfrac{}{}{0ex}{}{\text{2}}{\text{<figure-callout id="2" label="t d" filenames="00000054.png" state="{{state}}">t </figure-callout>}}$ d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ •

Finally we have
d ₁ = d _vp •

In all formulas, the proportionality coefficients are interconnected by a certain dependence through the value of the golden ratio Φ
i.e.

1,618= Φ;
2,618= (Φ)².1,272

1.618 = Φ;
2.618 = (Φ) ² .

 The concept of the golden ratio follows from the most important property of Fibonacci numbers.

m

1,618 φ где a_n числа Фибончачи.

m

1,618 φ where a _{n is} the Fibonacci number.

 Recall that a series of Fibonacci numbers has the form: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. etc.

m

≃

≃

≃

≃

≃

1,618 φ
Количество отверстий перфорации ми принимаем равным одному из чисел ряда Фибоначчи.Means

m

≃

≃

≃

≃

≃

1,618 φ
The number of perforation holes is taken equal to one of the numbers of the Fibonacci series.

 Thus, the perforation parameters of all internal elements of the muffler (inlet pipe, two partitions and exhaust pipe) are determined by a single method using Fibonacci numbers and the golden ratio, and at the same time they are linked to the dimensions of the diameter of the intake pipe, and therefore, to the volume of the cylinders of the internal combustion engine .

_{PRI me} R A. Diameter of the inlet pipe d _v.p. = 90 mm, inlet section F ₁ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ = 8 100 mm ² .

1. The calculation of the inlet pipe. We take z ₁ = 34.

90•

17,40 мм Проверка
F₁=

• Z₁=

• 34 8088,0 мм² В результате 8100 ≃ 8088
2. Расчет первой перфорированной поперечной перегородки:
Принимаем
d₂=

10,75 мм
Z₂=2,618 · Z₁|89 Проверка
F₂=

• Z₂=

• 89 8080,04 мм² В результате 8088 ≃ 8080,04
3. Расчет второй перфорированной поперечной перегородки
d₃=

6,64 мм
Z₃=2-618 X₂233
Проверка
F₃=

• Z₃=

• 233 8064,20 мм² В результате 8080 ≃ 8064,20
4. Расчет выпускного патрубка
Z₄=2,618 · Z₃|610
d₄= d_в.п•

90

4,10 мм Проверка
F₄=

• Z₄=

• 610 8064,62 мм В результате 8080 ≃ 8064,62 Вывод: F₁ ≃ F₂ ≃ F₃ ≃ F₄ ≃const, что и требовалось доказать.Then
d ₁ = d _vp •

90 •

17.40 mm Check
F ₁ =

• Z ₁ =

• 34 8088.0 mm ² As a result of 8100 ≃ 8088
2. The calculation of the first perforated transverse septum:
Accept
d ₂ =

10.75 mm
Z ₂ = 2,618 · Z ₁ | 89 Check
F ₂ =

• Z ₂ =

• 89 8080.04 mm ² As a result of 8088 ≃ 8080.04
3. The calculation of the second perforated transverse septum
d ₃ =

6.64 mm
Z ₃ = 2-618 X ₂ 233
Check
F ₃ =

• Z ₃ =

• 233 8064.20 mm ² As a result of 8080 ≃ 8064.20
4. The calculation of the exhaust pipe
Z ₄ = 2,618 · Z ₃ | 610
d ₄ = d _vp •

90

4.10 mm check
F ₄ =

• Z ₄ =

• 610 8064.62 mm As a result, 8080 ≃ 8064.62 Conclusion: F ₁ ≃ F ₂ ≃ F ₃ ≃ F ₄ ≃const, as required.

Take F ₁ <1.272 _f.p. for example, F ₁ = 1,1 d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ . impractical for design reasons.

Take F ₁ > 1.272 _f.e. e.g. F ₁ = 1.5 d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ also does not make sense, since in this case, overestimated dimensions of all internal elements and, accordingly, the silencer body are obtained.

, отвечает требованиям международного стандарта на предпочтительные числа и ГОСТ 8032-56, которым установлены четыpе ряда предпочтительных чисел, обозначаемых R5; R10; R20 и R40 (Харламов С. В. Конструирование технологических машин пищевых производств: Учебн. пособ. для вузов. Л. Машиностроение, 1979. 224 с.).On the other hand, the value of the coefficient of proportionality equal to 1.272 =

, meets the requirements of the international standard for preferred numbers and GOST 8032-56, which established four series of preferred numbers, designated R5; R10; R20 and R40 (Kharlamov S. V. Design of technological machines for food production: Textbook. For universities. L. Mechanical Engineering, 1979. 224 p.).

для R20 q 1,127

для R40 q 1,065

Таким образом, расчет внутренних элементов глушителя предлагается выполнять на основе действующих международных стандартов. Здесь возможна унификация глушителей для разных типоразмеров двигателей внутреннего сгорания.For these sizes it is characteristic that the denominator of the geometric progression q is equal to 1.6, respectively; 1.25; 1.12 and 1.06 or more precisely:
for R 5 q = 1,618 = Φ
for R10 q 1.272

for R20 q 1.127

for R40 q 1,065

Thus, the calculation of the internal elements of the silencer is proposed to be performed on the basis of current international standards. Here, unification of silencers is possible for different sizes of internal combustion engines.

нельзя, так как это противоpечит законам математики.Take d ₁ ≠ d _c.p.

It’s impossible, because it contradicts the laws of mathematics.

 Only the fulfillment of all the distinguishing features, the calculation of the parameters of the perforation of the inlet pipe according to formulas (1) and (2) allow us to calculate the device with the highest noise suppression efficiency especially for diesel engines.

 This design allows you to increase the efficiency of the device, as well as to unify mufflers for the entire standard range of internal combustion engines.

Claims (1)

INTERNAL COMBUSTION ENGINE NOISE SILENCER, containing a cylindrical body with coaxial inlet and outlet pipes and at least two transverse perforated partitions dividing the body into expansion chambers, moreover, the partitions are made with a diameter of the perforation holes decreasing and the number of holes increasing to the side a the diameters d _{p the} holes of the perforation of the partitions are related by the ratio
d _p = 1,618 • d _{n + 1} ,
where n is the serial number of the partition, starting from the inlet pipe;
1,618 - coefficient of proportionality,
and the number Z _p holes of perforation of the partitions is determined by the dependence

where the brackets denote the integer part of the number;
2.618 - proportionality coefficient,
characterized in that the inlet and outlet pipes are partially located in the housing and made perforated, and their ends are respectively located on the transverse partitions, and the area of the passage sections of the perforation of the pipes is equal to the area of the passage sections of the perforation of the partitions and its value is determined by the dependence
F ₁ = d $\genfrac{}{}{0ex}{}{\text{2}}{\text{vp}}$ ,
where F ₁ - the area of the passage through the perforation of the inlet pipe;
d _{c . n .} - diameter of the inlet pipe,
the diameter d _{1 of the} holes of the perforation of the inlet pipe is made in accordance with the ratio

where Z ₁ - the number of holes of the perforation of the inlet pipe;
1.272 - coefficient of proportionality.

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