Method for evaluating noise reduction effect of railway totally-enclosed sound barrier

Abstract

The invention discloses a method for evaluating the noise reduction effect of a railway totally-enclosed sound barrier, and belongs to the technical field of environmental protection. The method comprises the following steps: (1) determining reverberant sound in the totally-enclosed sound barrier; (2) determining a total sound field in the totally-enclosed sound barrier; and (3) calculating the noise of the full-closed sound barrier section. According to the method for evaluating the noise reduction effect of the railway totally-enclosed sound barrier, direct sound inside the totally-enclosed sound barrier when a train passes is calculated on the basis of directional characteristics of a high-speed pneumatic dipole and a wheel track noise approximate dipole, internal noise characteristics of the totally-enclosed sound barrier are obtained, finally on the basis of a sound insulation theory and a limited long sound source radiation model, a simplified calculation model of the noise reduction effect of the closed sound barrier is constructed, rapid calculation of the noise reduction effect of the closed sound barrier is achieved, and support is provided for optimization design, popularization and application of the closed sound barrier of the high-speed railway.

Description

technical field

[0001] The invention relates to a noise reduction effect evaluation method of a fully enclosed railway sound barrier, which belongs to the technical field of environmental protection. Background technique

[0002] Noise barrier is the most commonly used noise control measure in the railway industry. The most basic starting point of sound barrier control technology is to block the transmission path from the sound source to the sound receiver, so as to reduce the impact of railway noise.

[0003] However, the vertical sound barriers used in large numbers only have a certain noise reduction effect on the sound shadow area. For areas with greater noise impact, urban rail transit has adopted a large number of fully enclosed sound barriers, semi-enclosed sound barriers, etc. to further reduce the noise of the noise. Barrier types, the railway industry is also gradually studying the feasibility of fully enclosed and semi-enclosed sound barriers. The semi-enclosed sou...

Examples

Embodiment 1

[0070] Embodiment 1 (at low speed, when the wheel-rail noise source is the main source)

[0071] A method for evaluating the noise reduction effect of a fully enclosed railway sound barrier, the steps of which are as follows:

[0072] (1) Determination of the reverberation sound inside the fully enclosed sound barrier

[0073] 1) Calculation of the mean free path inside the fully enclosed sound barrier:

[0074]

[0075] Where: y 1 、y 2 - the distance from both ends of the sound barrier to the sound receiving point (along the direction of the line);

[0076] a, b——The section width and height of the fully enclosed sound barrier.

[0077] 2) Calculation of average sound energy density of reverberation sound:

[0078]

[0079] In the formula: W——the sound power of the line sound source per unit length;

[0080] L - EMU length;

[0081] V——The internal volume of the fully enclosed sound barrier in the train passing area V=LS, where S is the cross-sectional area of ​​th...

technical field

[0001] The invention relates to a noise reduction effect evaluation method of a fully enclosed railway sound barrier, which belongs to the technical field of environmental protection. Background technique

[0002] Noise barrier is the most commonly used noise control measure in the railway industry. The most basic starting point of sound barrier control technology is to block the transmission path from the sound source to the sound receiver, so as to reduce the impact of railway noise.

[0003] However, the vertical sound barriers used in large numbers only have a certain noise reduction effect on the sound shadow area. For areas with greater noise impact, urban rail transit has adopted a large number of fully enclosed sound barriers, semi-enclosed sound barriers, etc. to further reduce the noise of the noise. Barrier types, the railway industry is also gradually studying the feasibility of fully enclosed and semi-enclosed sound barriers. The semi-enclosed sou...

Examples

Embodiment 1

[0070] Embodiment 1 (at low speed, when the wheel-rail noise source is the main source)

[0071] A method for evaluating the noise reduction effect of a fully enclosed railway sound barrier, the steps of which are as follows:

[0072] (1) Determination of the reverberation sound inside the fully enclosed sound barrier

[0073] 1) Calculation of the mean free path inside the fully enclosed sound barrier:

[0074]

[0075] Where: y 1 、y 2 - the distance from both ends of the sound barrier to the sound receiving point (along the direction of the line);

[0076] a, b——The section width and height of the fully enclosed sound barrier.

[0077] 2) Calculation of average sound energy density of reverberation sound:

[0078]

[0079] In the formula: W——the sound power of the line sound source per unit length;

[0080] L - EMU length;

[0081] V——The internal volume of the fully enclosed sound barrier in the train passing area V=LS, where S is the cross-sectional area of ​​th...

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