A calibrated sound source device for high-speed airflow

Abstract

The present invention provides a calibration sound source device for high-speed airflow, which is used to calibrate the noise test system during aerodynamic noise wind tunnel tests, and can improve the accuracy and efficiency of noise source positioning. The device includes a fairing assembly, a support frame, a speaker, a sound-transmitting channel and a support rod. The fairing assembly is provided with a sound-transmitting hole, the speaker and the support frame are both installed inside the fairing assembly, the speaker is fixedly connected to the support frame, the sound-emitting part of the speaker is connected to the entrance of the sound-transmitting channel, the sound-transmitting channel is fixedly connected to the support frame, the outlet of the sound-transmitting channel is connected to the sound-transmitting hole on the fairing assembly, and one end of the support rod passes through the fairing assembly and is fixedly connected to the support frame; the sound-transmitting hole is covered with a layer of Carvra cloth. The device has the advantages of small sound-emitting area and good directivity.

Description

Technical Field

[0001] The invention belongs to the technical field of noise measurement and relates to a calibration sound source device used in high-speed airflow. Background Art

[0002] When conducting aerodynamic noise tests in acoustic wind tunnels, on the one hand, it is necessary to calibrate the noise test system on site to ensure that the noise test system works normally under the action of high-speed airflow. On the other hand, high-speed airflow will affect the propagation of sound waves, change its propagation direction and intensity, and affect the noise test results. Therefore, it is necessary to obtain the influence of high-speed airflow on the noise test results and make corresponding corrections and processing. Conventional calibration sound sources are usually spherical or square sound sources, which have the disadvantages of large volume, poor aerodynamic shape, and large sound source area. When arranged in high-speed airflow, they are subject to large aerodynamic forces, serious disturbances to the flow field, and will generate additional interference noise, which is difficult to meet the needs of calibrating the noise test system in high-speed airflow. The present invention designs a calibration sound source that can be used in high-speed airflow, which has a good aerodynamic shape, low aerodynamic load, and does not generate additional aerodynamic noise; it uses a high-intensity loudspeaker to generate sound, which has the advantages of wide frequency range, strong sound generation ability, stable sound generation effect, and controllable sound generation mode; the sound waves radiate noise through the sound-permeable holes, which has the advantages of small sound source area and good directivity. This calibration sound source can be used for a variety of purposes, such as noise test system inspection and calibration, airflow influence analysis and correction, and microphone phase array performance evaluation under airflow conditions. It can improve the accuracy of noise measurement in acoustic wind tunnels. Summary of the invention

[0003] In view of the above shortcomings, the present invention provides a calibration sound source device for high-speed airflow, which is used to calibrate the noise test system during aerodynamic noise wind tunnel testing, and can improve the accuracy and efficiency of noise source positioning.

[0004] The technology adopted by the present invention is as follows: a calibration sound source device for high-speed airflow, including a fairing assembly, a support frame, a speaker, a sound-transmitting channel and a support rod, the fairing assembly is provided with a sound-transmitting hole, the speaker and the support frame are installed inside the fairing assembly, the speaker is fixedly connected to the support frame, the sound-emitting part of the speaker is connected to the entrance of the sound-transmitting channel, the sound-transmitting channel is fixedly connected to the support frame, the outlet of the sound-transmitting channel is connected to the sound-transmitting hole on the fairing assembly, and one end of the support rod passes through the fairing assembly and is fixedly connected to the support frame; the sound-transmitting hole is covered with a layer of kevlar cloth.

[0005] The present invention also has the following technical features:

[0006] 1. The fairing assembly as described above comprises front, middle and rear fairings, and the interiors of the front, middle and rear fairings are respectively fixedly connected to the support frame.

[0007] 2. The loudspeaker as described above is installed inside the middle fairing, and the sound-permeable hole is opened on the middle fairing.

[0008] 3. The fairing assembly as described above is an elliptical spiral structure, and the cross-section of the fairing assembly corresponds to the airfoil curve.

[0009] 4. The other end of the support rod as described above is a cone sleeve structure.

[0010] 5. As mentioned above, a wiring channel is provided inside the support rod.

[0011] The advantages and beneficial effects of the present invention are as follows: the present invention is used to calibrate the noise test system during the aerodynamic noise wind tunnel test, and improves the accuracy and efficiency of noise source positioning. It is convenient to arrange in high-speed airflow, while reducing the interference to the flow field and avoiding the generation of additional noise interference; secondly, it adopts a high-intensity electric speaker to generate sound, which has the advantages of strong sound generation ability, stable sound generation effect, and reliable sound generation mode; at the same time, it has the advantages of small sound generation area and good directivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The structure diagram of a calibration sound source device for high-speed airflow according to the present invention;

[0013] 1- fairing, 2- sound hole, 3- speaker, 4- support frame, 5- sound channel, 6- support rod DETAILED DESCRIPTION

[0014] The present invention is further described below with reference to the accompanying drawings:

[0015] Example 1

[0016] like Figure 1As shown, a calibration sound source device for high-speed airflow includes a fairing assembly, a support frame, a speaker, a sound-transmitting channel and a support rod. The fairing assembly is provided with a sound-transmitting hole. The speaker and the support frame are both installed inside the fairing assembly. The speaker is fixedly connected to the support frame. The sound-emitting part of the speaker is connected to the entrance of the sound-transmitting channel. The sound-transmitting channel is fixedly connected to the support frame. The outlet of the sound-transmitting channel is connected to the sound-transmitting hole on the fairing assembly. One end of the support rod passes through the fairing assembly and is fixedly connected to the support frame. The sound-transmitting hole is covered with a layer of Carvra cloth. The fairing assembly includes front, middle and rear fairings, each of which is fixedly connected to the support frame by screws. The middle fairing is divided into two halves along the axial direction to facilitate the installation, wiring and maintenance of the speaker. The speaker is installed inside the middle fairing, and the sound-transmitting hole is opened on the middle fairing. The fairing assembly is an elliptical spiral body structure, and the cross-section of the fairing assembly corresponds to the airfoil curve. The other end of the support rod is a cone sleeve structure, which enables the installation of the calibration sound source in the airflow in test occasions such as wind tunnels. A wiring channel is opened inside the support rod for arranging the speaker signal line. The sound-transmitting channel is used to transmit the sound waves generated by the speaker out of the fairing to form a point sound source; the support rod is used to connect other equipment to achieve the installation of the calibration sound source in wind tunnels and other occasions. The speaker is connected to the support frame by screws, a high-intensity speaker is used, and a sealing ring is used at the connection part for sealing treatment; the sound-emitting part of the speaker is connected to the entrance of the sound-transmitting channel, and the sound waves generated can enter the sound-transmitting channel; the sound-transmitting channel is fixedly connected to the support frame by screws, and a sealing ring is used at the connection part for sealing treatment; a layer of Kevlar cloth is covered on the sound-transmitting hole to separate the airflow and prevent high-speed airflow from rushing into the sound-transmitting channel 5 to generate strong noise interference, while also allowing the sound waves generated by the speaker to be transmitted out. This embodiment uses a fairing with a good aerodynamic shape to separate the airflow, reduce the aerodynamic force on the calibration sound source, and reduce the interference to the flow field to avoid additional noise interference. The sound waves generated by the speaker are transmitted outward along the sound-permeable channel and radiated through the sound-permeable hole to reduce the sound source area and ensure its directivity at high frequencies. The fairing assembly is divided into sections and blocks to facilitate the installation, wiring and maintenance of the internal speakers.

Claims

1. A calibration sound source device for high-speed airflow, comprising a fairing assembly, a support frame, a speaker, a sound-transmitting channel and a support rod, characterized in that: The fairing assembly is provided with a sound-permeable hole, the speaker and the support frame are installed inside the fairing assembly, the speaker is fixedly connected to the support frame, the sound-emitting part of the speaker is connected to the entrance of the sound-permeable channel, the sound-permeable channel is fixedly connected to the support frame, the outlet of the sound-permeable channel is communicated with the sound-permeable hole on the fairing assembly, and one end of the support rod passes through the fairing assembly and is fixedly connected to the support frame; the sound-permeable hole is covered with a layer of Kevlar cloth.

2. A calibration sound source device for high-speed airflow according to claim 1, characterized in that: The fairing assembly comprises front, middle and rear fairings, and the interiors of the front, middle and rear fairings are respectively fixedly connected to the support frame.

3. A calibration sound source device for high-speed airflow according to claim 2, characterized in that: The loudspeaker is installed inside the middle fairing, and the sound-permeable hole is opened on the middle fairing.

4. A calibration sound source device for high-speed airflow according to any one of claims 1 to 3, characterized in that: The fairing assembly is an elliptical spiral structure, and the cross section of the fairing assembly corresponds to the airfoil curve.

5. A calibration sound source device for high-speed airflow according to any one of claims 1 to 3, characterized in that: The other end of the support rod is a cone sleeve structure.

6. A calibration sound source device for high-speed airflow according to any one of claims 1 to 3, characterized in that: A wiring channel is provided inside the support rod.

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