METHOD AND DEVICES FOR TESTING FLAMMABILITY

Abstract

Methods and equipment for conducting flammability tests are provided. A flammability test apparatus comprises a wind tunnel with a test chamber having a first and a second wall, wherein the first wall includes a lateral opening, an upstream module, a downstream module, and flexible channels connecting the test chamber and the modules.The device further comprises a coupon configured to seal the side opening; a fan configured to draw air from the downstream module; a flow restrictor configured to limit the airflow into the upstream module, the fan and flow restrictor being configured to maintain a selected flow velocity and pressure in the test chamber adjacent to a rear side of the coupon; a flamethrower configured to direct a flame toward the front side of the coupon; and a shaking platform configured to apply an excitation input to the test chamber.

Description

TECHNICAL AREA

[0001] The technical field generally relates to the testing of flammability and in particular to a device for carrying out flammability tests on a test object and to methods for carrying out flammability tests. BACKGROUND

[0002] Various authorities around the world are responsible for establishing and enforcing civil aviation regulations. These regulations include extensive safety requirements for transport aircraft. Implementing and enforcing these civil aviation regulations is significantly more complex and costly than the regulations issued by other regulatory bodies for land and water vehicles.

[0003] Required tests for transport category aircraft include flammability tests. These tests apply to various components with regard to their use and sometimes also to the materials from which the components are made.

[0004] Therefore, certain tests require the creation of flight conditions around a test object while it is exposed to a flame. For example, an airflow can be directed towards the test object to create pressures and velocities similar to those of a typical flight while the test object is exposed to a flame.

[0005] Due to the wide variety of items to be tested, test fixtures are usually built ad hoc and tailored to the specific item under test, including its size and shape. Such a process is time-consuming, expensive, and may not yield sufficient test results.

[0006] Accordingly, it is desirable to provide flammability testing devices and procedures that solve one or more of the aforementioned problems. Furthermore, other desirable features and properties of the various embodiments described herein will become apparent from the following detailed description and the accompanying claims in conjunction with the accompanying drawings and this background information. SUMMARY

[0007] This document provides various non-restrictive embodiments of methods and devices for carrying out flammability tests.

[0008] In a first non-restrictive embodiment, a flammability test device comprises a wind tunnel with a test chamber having a first and a second wall, wherein the first wall has a lateral opening, an upstream module, a downstream module and flexible channels connecting the test chamber and the modules.The device further comprises a coupon configured to seal the side opening; a fan configured to draw air from the downstream module; a flow restrictor configured to limit the airflow into the upstream module, the fan and flow restrictor being configured to maintain a selected flow velocity and pressure in the test chamber at a rear side of the coupon; a flamethrower configured to direct a flame at a front side of the coupon; and a vibrating platform configured to apply excitation input to the test chamber.

[0009] In certain embodiments of the flammability testing device, the coupon includes or holds a test item that is subjected to a flammability test.

[0010] In certain embodiments of the flammability test device, the second wall includes a transparent window for viewing the reverse side of the coupon.

[0011] In certain embodiments of the flammability test device, the wind tunnel has an internal height within the upstream module; the wind tunnel has an internal height within the downstream module; the wind tunnel has a test internal height within the test chamber; and the internal height in the upstream module and the internal height in the downstream module are substantially the same in order to reduce turbulent airflow through the wind tunnel.

[0012] In certain embodiments, the flammability test device further comprises an upstream channel width adjustment module connecting the upstream flexible channel and the test chamber, and a downstream channel width adjustment module connecting the test chamber and the downstream flexible channel.

[0013] In certain embodiments of the flammability test device, the upstream module comprises two interconnected upstream chambers; and the downstream module comprises two interconnected downstream chambers.

[0014] In certain embodiments, the flammability testing device further comprises a bypass valve formed in the downstream module and a control module configured to set a fan speed of the fan or ventilator, a throttling range of the flow limiter and a bypass range of the bypass valve.

[0015] In certain embodiments, the flammability test device further includes sensors arranged in the test chamber to monitor temperature and pressure.

[0016] In a further, non-restrictive embodiment, a method for performing a flammability test comprises preparing a wind tunnel, which includes: a test chamber with a first wall and a second wall opposite the first wall, the first wall comprising a lateral opening; an upstream module arranged upstream of the test chamber; and a downstream module arranged downstream of the test chamber; attaching a coupon in the lateral opening, the coupon comprising or holding a test item on which the flammability test is performed, and wherein a rear side of the coupon is in fluid communication with an interior of the test chamber; extracting air from the downstream module with a fan; limiting the airflow into the upstream module with a flow restrictor; and applying a flame to a front side of the coupon.

[0017] In certain embodiments of the method for performing a flammability test, the preparation of the wind tunnel further comprises connecting an upstream flexible channel between the test chamber and the upstream module; connecting a downstream flexible channel between the test chamber and the downstream module; and applying an excitation input to the test chamber, wherein the upstream flexible channel isolates the upstream module from the excitation input and wherein the downstream flexible channel isolates the downstream module from the excitation input.

[0018] In certain embodiments of the method for performing a flammability test, the preparation of the wind tunnel further comprises determining a desired internal diameter of the test chamber; assembling the test chamber with the desired internal diameter; connecting the test chamber to the upstream flexible duct with an upstream duct diameter adjustment module; and connecting the test chamber to the downstream flexible duct with a downstream duct diameter adjustment module; wherein the duct diameter adjustment modules eliminate or reduce turbulent airflows in the test chamber.

[0019] In certain embodiments of the method for carrying out a flammability test, the downstream module is equipped with a bypass valve, and the method further includes setting a fan speed of the fan or ventilator, a throttling range of the flow limiter and a bypass range of the bypass valve.

[0020] In certain embodiments, the method for carrying out a flammability test further includes monitoring temperature and pressure with sensors in the test chamber.

[0021] In certain embodiments, the method for carrying out a flammability test further comprises the manufacture of the coupon, wherein the side opening has a selected shape and size, and wherein the coupon is manufactured with a suitable shape and size to close the side opening.

[0022] In certain embodiments of the method for performing a flammability test, the test object is an aircraft component.

[0023] In certain embodiments of the method for carrying out a flammability test, the preparation of the wind tunnel comprises providing the upstream module with an internal height, providing the downstream module with an internal height, and providing the test chamber with a test internal height, wherein the internal height in the upstream module and the internal height in the downstream module are substantially the same in order to reduce turbulent airflows through the wind tunnel.

[0024] In a further non-restrictive embodiment, a method for performing a flammability test comprises assembling a test chamber with a desired internal diameter, wherein the test chamber is configured with an opening; arranging the test chamber on a vibrating platform; connecting the test chamber to an upstream module via a flexible channel, wherein the upstream module is not located on the vibrating platform; connecting the test chamber to a downstream module via a flexible channel, wherein the downstream module is not located on the vibrating platform; securing a coupon in the opening, wherein the coupon comprises or holds a test article on which the flammability test is performed, and wherein a rear side of the coupon is in fluid communication with an interior of the test chamber; and extracting air from the downstream module with a fan.Limiting or throttling the airflow into the upstream module with a flow restrictor; applying a flame to one side of the coupon; and applying an excitation input to the test chamber with the vibrating platform.

[0025] In certain embodiments, the method for performing a flammability test further includes setting a rotational speed of the fan and a throttling range of the flow restrictor in order to set a pressure in the test chamber.

[0026] In certain embodiments, the method for carrying out a flammability test further includes monitoring the temperature and pressure with sensors in the test chamber.

[0027] In certain embodiments, the method for carrying out a flammability test further comprises manufacturing the coupon, wherein the opening has a selected shape and size, and wherein the coupon is manufactured with a suitable shape and size to seal the opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The various embodiments are described below in conjunction with the following figures, where the same reference numerals denote the same elements and where: Fig. 1 is a simplified schematic top view showing a flammability testing device according to an exemplary embodiment; Fig. 2 a schematic cross-sectional view of the flammability test device made of Fig. 1 according to an exemplary embodiment; Fig. 3 an exploded view of a test chamber of the flammability test device Fig. 1 and Fig. 2 according to an exemplary embodiment; Fig. 4 a perspective view of the lower half of the assembled test chamber of the flammability test device Fig. 1 and Fig. 2 according to an exemplary embodiment; and Fig. 5 a top view of the assembled test chamber of the flammability test device Fig. 1 and Fig. 2 according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] The following detailed description is merely exemplary and is not intended to limit the various embodiments or their application and use. Furthermore, there is no intention to be bound by the theories set forth in the preceding background description or the following detailed description.

[0030] The exemplary embodiments described herein are intended for use with fairings or other components of vehicles, for example aircraft or the like.

[0031] The exemplary embodiments described herein provide a device for performing flammability tests on various test objects or items despite structural differences between them. For example, the test objects may have different shapes and sizes. Therefore, the assembly may include a universal opening for receiving a coupon that is or holds the test object or item. The coupon is dimensioned to fit into the universal opening to seal or close the opening during the test.

[0032] Adaptability is further enhanced by the use of a reconfigurable test chamber or test section. In addition to changes in the size and shape of the test piece, the test chamber is provided with an adjustable depth (in the horizontal direction perpendicular to the direction of the airflow 101). For example, the inlet of the test chamber can be adjustable to ensure a suitable airflow through a desired depth. Furthermore, in certain embodiments, the length of the test chamber is adjustable. Certain embodiments also include instrumentation and / or viewing windows or inserts.

[0033] The embodiments described herein offer increased test accuracy. These embodiments decouple the test pressure and test airflow velocities using control loops. In certain embodiments, the vertical height of the airflow duct is kept constant by an upstream module, the test chamber, and a downstream module. In certain embodiments, the test chamber is connected to the upstream and downstream modules via a flexible duct or a connection.

[0034] Furthermore, the flammability test device prevents air from being recirculated through the test chamber. In other words, the air flowing through the test chamber is diverted and not returned to the flammability test device. This keeps the airflow clean and reduces false alarms.

[0035] Fig. Figure 1 is a schematic top view of a flammability testing device 40. Fig. Figure 2 is a schematic cross-sectional view of the flammability test device 40. Fig. 1. As shown, the flammability test apparatus 40 comprises a wind tunnel 100, which limits or defines an inner channel 102, a fan 70 configured to draw air out of the wind tunnel 100 as an airflow 101, a flow restrictor 60 configured to limit the airflow 101 into the wind tunnel 100, a flamethrower 50, a vibrating platform 80, and a control module or data acquisition system (DAS) 30 configured to adjust the fan speed of the fan 70 and the throttling range of the flow restrictor 60 to control and maintain a selected flow velocity and pressure in the wind tunnel 100. The airflow 101 flows through the inner channel 102 defined by the wind tunnel 100.

[0036] The wind tunnel 100 comprises a test or inspection chamber or a test section 500. As in Fig. As shown in Figure 1, the test chamber 500 has a first wall 501 and an opposing second wall 502. In exemplary embodiments, the first wall 501 and the second wall 502 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 501 and 502 as non-planar and / or non-parallel. The first wall 501 of the test chamber 500 is formed with a lateral opening 590, i.e., an opening 590 in the horizontal direction perpendicular to the direction of the airflow 101.

[0037] The flammability test device 40 further comprises a coupon 90 configured to cover the lateral opening 590 in the first wall 501 of the test chamber 500. The coupon 90 can be a test object or form a test object subjected to the flammability test. In other embodiments, the coupon 90 can hold a test object subjected to a flammability test. For example, the test object can be an outer skin of an aircraft. In such cases, the skin itself is shaped to fit into and seal the opening 590 as the coupon 90. In other cases, it is desirable to perform a flammability test on a smaller object that is not large enough to cover the opening 590. In such cases, the smaller component, i.e., the test object, is held by the coupon 90.In any case, coupon 90 and the test object have a reverse side 92 facing the interior of test chamber 500, and a front side 91 facing the flamethrower 50.

[0038] In certain embodiments, the second wall 502 of the test chamber 500 includes a transparent window 580 for viewing the interior of the test chamber 500 and, in particular, for viewing the rear side 92 of the test object 90.

[0039] As in Fig. As further shown in Figure 1, the test chamber can include 500 sensors 930 for monitoring the conditions within the test chamber 500. For example, the sensors 930 can include thermocouples, pressure transducers, pitot tubes for measuring static and dynamic pressures and other conditions.

[0040] The 930 sensors can be connected to the 30 data acquisition system (DAS). Furthermore, the 930 sensors can provide two data sets: a control system data set used for controlling the test fixture and a data system data set recorded as test results.

[0041] As in Fig. As shown in Figure 1, the first wall 501 is separated from the second wall 502 by a width D5 in the horizontal direction, perpendicular to the direction of the airflow 101. As described below, the test chamber 500 can be configured to provide a desired width D5 within the test chamber 500 without reconfiguring the rest of the wind tunnel 100. In certain embodiments, the adjusted width D5 can be between 1.9 cm (0.75 in) and 10.2 cm (4 in), for example, 7.6 cm (3 in).

[0042] As in Fig. As shown in Figure 2, the test chamber 500 has a third wall or ceiling 503 and an opposing fourth wall or floor 504. In exemplary embodiments, the third wall 503 and the fourth wall 504 are flat, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 503 and 504 as non-flat and / or non-parallel.

[0043] The third wall 503 is separated from the fourth wall 504 by a height H5 in the vertical direction perpendicular to the direction of the airflow 101. In certain embodiments, the height H5 can be between 30.5 cm (12 in) and 90.4 cm (36 in), for example 60.1 cm (24 in).

[0044] In the Fig. 1 and Fig. 2. Wind tunnel 100 further comprises an upstream module 200 located upstream of test chamber 500. As shown, the upstream module 200 comprises two upstream sections 210; however, the upstream module 200 can be formed from any number of sections 210. The sections 210 can be fitted together and / or connected to each other.

[0045] In exemplary embodiments, an airflow straightener 220 can be located between the two sections 210 to eliminate turbulence downstream of the flow restrictor 60.

[0046] In Fig. 1 Each section 210 of the upstream module 200 comprises a first wall 201 and an opposing second wall 202. In exemplary embodiments, the first wall 201 and the second wall 202 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 201 and 202 as non-planar and / or non-parallel. As shown, the first wall 201 is separated from the second wall 202 by a width D2. In certain embodiments, the width D2 can be between 15.2 cm (6 in) and 45.7 cm (18 in).

[0047] In Fig. 2 Each section 210 of the upstream module 200 comprises a third wall or ceiling 203 and an opposing fourth wall or floor 204. In exemplary embodiments, the third wall 203 and the fourth wall 204 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 203 and 204 as non-planar and / or non-parallel. As shown, the third wall 203 is separated from the fourth wall 204 by a height H2 in the vertical direction perpendicular to the direction of the airflow 101. In certain embodiments, the height H2 can be between 30.5 cm (12 in) and 90.4 cm (36 in), for example, 60.1 cm (24 in).

[0048] In the Fig. 1 and Fig. 2 The flammability test device 40 further comprises an upstream transition section 160. The upstream transition section 160 is provided between the flow restrictor 60 and the upstream module 200. In particular, the transition section 160 has an inlet 161 for receiving the airflow 101 from the flow restrictor 60 and an outlet 162 connected to the upstream module 200. The inlet 161 can have a vertical height and a lateral depth configured to correspond to the diameter of the flow restrictor 60. The transition section 160 increases continuously in height and width up to the outlet 162, which has a vertical height and a lateral width corresponding to the height H2 and width D2 of the upstream module 200.

[0049] In the Fig. 1 and Fig. 2 The flammability test device 40 further comprises an upstream flexible channel 300, which is provided to connect the test chamber 500 and the upstream module 200. The flammability test device 40 also further comprises an upstream channel width adjustment module or nozzle 400, which is provided to connect the test chamber 500 and the upstream module 200. In particular, in the illustrated embodiment, the upstream module 200 is directly connected to the upstream flexible channel 300, the upstream flexible channel 300 is directly connected to the upstream nozzle 400, and the upstream nozzle 400 is directly connected to the test chamber 500.

[0050] The upstream flexible channel 300 is made of rubber or another non-rigid elastomeric material. This prevents vibrations or other mechanical forces from being transmitted from the test chamber 500 to the upstream module 200.

[0051] As in Fig. As shown in Figure 1, the upstream flexible channel 300 comprises a first wall 301 and an opposing second wall 302. In exemplary embodiments, the first wall 301 and the second wall 302 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 301 and 302 as non-planar and / or non-parallel. As shown, the first wall 301 is separated from the second wall 302 by a distance D2.

[0052] As in Fig. As shown in Figure 2, the upstream flexible duct 300 comprises a third wall or ceiling 303 and an opposing fourth wall or floor 304. In exemplary embodiments, the third wall 303 and the fourth wall 304 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 303 and 304 as non-planar and / or non-parallel. As shown, the third wall 303 is separated from the fourth wall 304 by a height H2 in the vertical direction, perpendicular to the direction of the airflow 101.

[0053] As in Fig. As shown in Figure 1 and described below, the upstream nozzle 400 is designed to gradually reduce the width of the inner channel 102 in the direction of the airflow 101 from width D2 to width D5, while simultaneously generating a laminar airflow and / or minimizing turbulent airflow. The upstream nozzle 400 comprises a first wall 401 and an opposing second wall 402. In exemplary embodiments, the first wall 401 and the second wall 402 are curved. As shown, the first wall 401 is separated from the second wall 402 by width D2 at the interface with the flexible channel 300. Furthermore, the first wall 401 is separated from the second wall 402 by width D2 at the interface with the test chamber 500.

[0054] As in Fig. As shown in Figure 2, the upstream nozzle 400 comprises a third wall or ceiling 403 and an opposing fourth wall or floor 404. In exemplary embodiments, the third wall 403 and the fourth wall 404 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both walls 403 and 404 as non-planar and / or non-parallel. As shown, the third wall 403 is separated from the fourth wall 404 by a height H2 in the vertical direction, perpendicular to the direction of the airflow 101.

[0055] In the Fig. 1 and Fig. 2. Wind tunnel 100 further comprises a downstream module 800 located downstream of test chamber 500. As shown, the downstream module 800 comprises two downstream sections 810; however, the downstream module 800 can be formed from any number of sections 810. The sections 810 can be fitted together and / or connected to each other.

[0056] In Fig. 1 Each section 810 of the downstream module 800 comprises a first wall 801 and an opposing second wall 802. In exemplary embodiments, the first wall 801 and the second wall 802 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 801 and 802 as non-planar and / or non-parallel. As shown, the first wall 801 is separated from the second wall 802 by a width D8. In exemplary embodiments, the width D8 is equal to the width D2.

[0057] In Fig. 2 Each section 810 of the downstream module 800 comprises a third wall or ceiling 803 and an opposing fourth wall or floor 804. In exemplary embodiments, the third wall 803 and the fourth wall 804 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 803 and 804 as non-planar and / or non-parallel. As shown, the third wall 803 is separated from the fourth wall 804 by a height H8 in the vertical direction perpendicular to the direction of the airflow 101. In exemplary embodiments, the height H8 is equal to the heights H2 and H5.

[0058] In the Fig. 1 and Fig. 2 The flammability test device 40 further comprises a downstream transition section 870. The downstream transition section 870 is provided between the downstream module 800 and the fan 70. In particular, the downstream transition section 870 has an inlet 871 for receiving the airflow 101 from the downstream module 800 and an outlet 872 connected to the fan 70. The inlet 871 can have a vertical height and a lateral width configured to correspond to the height H8 and the width D8 of the downstream module 800. The transition section 870 decreases continuously in height and width towards the outlet 872, which has a vertical height and lateral width corresponding to the diameter of the fan 70.

[0059] In the Fig. 1 and Fig. 2 The flammability test device 40 further comprises a downstream flexible channel 700, which is provided for connecting the test chamber 500 and the downstream module 800. The flammability test device 40 also further comprises a downstream channel width adjustment module 600, which is provided for connecting the test chamber 500 and the downstream module 800. In particular, in the illustrated embodiment, the downstream module 800 is directly connected to the downstream flexible channel 700, the downstream flexible channel 700 is directly connected to the downstream channel width adjustment module 600, and the downstream channel width adjustment module 600 is directly connected to the test chamber 500.

[0060] The downstream flexible channel 700 is made of rubber or another non-rigid elastomeric material. This prevents vibrations or other mechanical forces from being transmitted from the test chamber 500 to the downstream module 800.

[0061] As in Fig. As shown in Figure 1, the downstream flexible channel 700 comprises a first wall 701 and an opposing second wall 702. In exemplary embodiments, the first wall 701 and the second wall 702 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 701 and 702 as non-planar and / or non-parallel. As shown, the first wall 701 is separated from the second wall 702 by a distance D8.

[0062] As in Fig. As shown in Figure 2, the downstream flexible duct 700 comprises a third wall or ceiling 703 and an opposing fourth wall or floor 704. In exemplary embodiments, the third wall 703 and the fourth wall 704 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 703 and 704 as non-planar and / or non-parallel. As shown, the third wall 703 is separated from the fourth wall 704 by a height H8 in the vertical direction, perpendicular to the direction of the airflow 101.

[0063] As in Fig. As shown in Figure 1 and described below, the downstream duct width adjustment module 600 is provided to gradually increase the width of the inner duct 102 in the direction of the airflow 101 from width D5 to width D8, while ensuring a laminar airflow and / or minimizing turbulent airflow. The downstream duct width adjustment module 600 comprises a first wall 601 and an opposing second wall 602. In exemplary embodiments, the first wall 601 and the second wall 602 are curved. As shown, the first wall 601 is separated from the second wall 602 by width D8 at the interface with the test chamber 500. Furthermore, the first wall 601 is separated from the second wall 602 by width D8 at the interface with the flexible duct 700.

[0064] As in Fig. As shown in Figure 2, the module 600 for adjusting the width of the downstream duct comprises a third wall or ceiling 603 and an opposing fourth wall or floor 604. In exemplary embodiments, the third wall 603 and the fourth wall 604 are planar, vertical, and parallel. It is conceivable that in certain embodiments it may be desirable to design one or both of the walls 603 and 604 as non-planar and / or non-parallel. As shown, the third wall 603 is separated from the fourth wall 604 by a height H8 in the vertical direction, perpendicular to the direction of the airflow 101.

[0065] The Fig. Show that the flammability test device 40 can have a bypass valve 820 on the downstream module 800. The bypass valve 820 can be opened or closed. When open, the bypass valve 820 defines a diversion flow area through which air can escape from the inner channel 102. The diversion flow area can be controlled to further adjust the pressure and velocity in the inner channel 102.

[0066] The control module 30 is configured to receive data from the sensors 930. Furthermore, the control module 30 is configured to send instructions or otherwise control the operation of the fan 70, the flow restrictor 60, and the bypass valve 820. For example, the control module 30 can control the fan speed of the fan 70, the flow limiting or throttling range of the flow restrictor 60, and the diverting flow range of the bypass valve 820. Consequently, the control module 30, the fan 70, the flow restrictor 60, and the bypass valve 820 can maintain a selected flow velocity and pressure in the wind tunnel 100 in general, and specifically in the test chamber 500 adjacent to the rear 92 of the coupon 90.

[0067] The flamethrower 50 is positioned and operated in such a way that it directs a flame towards the front 91 of the test object 90.

[0068] Furthermore, the vibration platform 80 is configured to provide an excitation input to the test chamber 500. As in Fig. As can be seen most clearly, test chamber 500 can rest on and be supported by the vibration platform 80. This allows the vibration platform 80 to shake and / or vibrate, thus generating the excitation input that is transmitted to test chamber 500. The channel width adjustment modules 400 and 600 can also be supported and shaken by the vibration platform 80. However, the flexible channels 300 and 700 absorb the excitation input and do not transmit it to modules 200 and 800. As shown in Fig. As shown in Figure 2, modules 200 and 800 are supported independently of each other by roller supports 209 and 809. This limits the impact of shocks or vibrations on structures to test chamber 500 and the channel width adjustment modules 400 and 600.

[0069] From the Fig. 1 and Fig. Figure 2 shows that the wind tunnel 100 has an upstream internal height H2 within the upstream module 200, a downstream internal height H8 within the downstream module 800, and a test internal height H5 within the test chamber 500. In certain embodiments, the upstream internal height H2, the downstream internal height H8, and the test internal height H5 are equal in order to reduce turbulent airflow through the wind tunnel 100. In other embodiments, the upstream internal height H2, the downstream internal height H8, and the test internal height H5 can vary. More precisely, the test internal height H5 can differ from the upstream internal height H2 and the downstream internal height H8.

[0070] Furthermore, the wind tunnel 100 features an upstream internal diameter D2 within the upstream module 200, a downstream internal diameter D8 within the downstream module 800, and a test internal diameter D5 within test chamber 500. The upstream internal diameter D2 and the downstream internal diameter D8 can be substantially the same to improve operation. The test internal diameter D5 is selected for the item or coupon being tested for flammability. In other words, the test internal diameter D5 is adjustable. Additionally, the channel diameter adjustment modules 400 and 600 provide a smooth transition in diameter to and from the D5 diameter of test chamber 500 to reduce turbulent airflow through test chamber 500.

[0071] In exemplary embodiments, the fan speed of the fan 70 and the throttling range of the flow restrictor 60 are controlled such that an airflow velocity 101 through the test chamber 500 of 0 to 5.8 m / s (190 ft / second), for example 5 m / s (165 ft / second), and a pressure in a width of 7.6 cm (3 in) in the test chamber of 0 to -124 hPa; for example -124 hPa (-1.8 psi) are maintained.

[0072] In an exemplary embodiment, the device is made from the Fig. 1 and Fig. 2 in a method for carrying out a flammability test. The method comprises forming the coupon 90 as a test specimen or together with the test specimen. The coupon 90 can be formed with a universal circumference for connection with the test chamber 500. In particular, the opening 590 in the test chamber 500 has a selected shape and size, and the coupon 90 is manufactured with a suitable shape and size to seal or cover the opening 590.

[0073] Based on the test specimen, a width D5 is determined for testing the specimen. In this procedure, the wind tunnel 100 is prepared by assembling the test chamber 500 with the desired width D5 between the first wall 501 and the second wall 502. The test chamber 500 is located on the vibration platform 80.

[0074] The test chamber 500 can then be attached to the channel width adjustment modules 400 and 600. The channel width adjustment modules 400 and 600 can be attached to the flexible channels 300 and 700 either before or after the test chamber 500 has been attached to the channel width adjustment modules 400 and 600.

[0075] The procedure then comprises placing the upstream module 200 upstream of the test chamber 500 and arranging the downstream module 800 downstream of the test chamber 500. The upstream module 200 is attached to the upstream flexible channel 300 and the downstream module 800 is attached to the downstream flexible channel 700.

[0076] Furthermore, the flow restrictor 60 is connected to the upstream module 200 and the fan 70 is connected to the downstream module 800.

[0077] The method further comprises attaching the coupon 90 in the side opening 590, wherein the front 91 of the coupon 90 forms an outer surface of the wind tunnel 100 and the back 92 of the coupon 90 borders the inside of the test chamber 500 and is in fluid communication with it.

[0078] The test begins by drawing air from the downstream module 800 using the fan 70, while the airflow into the upstream module 200 is throttled by the flow restrictor 60. The fan 70 and the flow restrictor 60 can be controlled to generate the desired pressures in the test chamber 500. Once the desired conditions are reached, the procedure involves applying the excitation input from the vibrating plate 80 to the test chamber 500 and applying a flame to the front 91 of the coupon 90. Typically, the test is performed for a selected duration, for example, fifteen minutes.

[0079] During the test, the sensors 930 record data, and the condition of the back 92 of the test piece 90 can be viewed through the window 580 and / or recorded on video. During the test, the flexible channels 300 and 700 isolate the modules 200 and 800 from the excitation input.

[0080] With reference to Fig. Figure 3 shows an exploded view of a test chamber 500. Note that the first wall 501 is shown without cladding to reveal the components behind it. As shown, a third wall (ceiling) 503 and a fourth wall (floor) 504 of a selected height are provided. The first wall 501 and the second wall 502 can be attached to the third wall 503 and the fourth wall 504. Thus, the height of the test chamber 500 is determined by selecting the third wall 503 and the fourth wall 504. In certain embodiments, a set of third and fourth walls 503 and 504 of different heights can be provided for selection.

[0081] As in Fig. As shown in Figure 3, the first wall 501 is configured with a lateral opening 590. The lateral opening 590 in the first wall 501 can be of a universal size and shape. For example, the opening 590 can be square, rectangular, or another suitable shape. Furthermore, the second wall 502 is configured with a transparent window 580 directly opposite the opening 590. The second wall 502 can also be configured with openings 560 for receiving inserts 570. The inserts 570 can include sensors, control modules, or other instruments. Thus, such components in the inserts 570 can be configured for use with a variety of second walls 502; that is, they are not exclusively intended for or limited to use with just one second wall 502.

[0082] In Fig. Figure 3 shows an adapter plate 591 inserted into and attached to the opening 590. As shown, the adapter plate 591 is annular, effectively reducing the size of the opening 590. The adapter plate 591 can be selected from a set of adapter plates 591 that have a universal outer diameter for engaging the opening 590 and different annular widths / lengths to provide different inner diameter sizes, enabling the testing of samples of varying sizes. In certain embodiments, the adapter plate 591 includes pins or extensions along the circumference of the reduced opening 590.

[0083] Furthermore, a seal 592 is accommodated on the projections of the adapter plate 591. For example, the seal 592 includes openings for receiving the projections. The seal 592 can be compressible to provide a tight seal between the coupon 90 and the adapter plate 591. Accordingly, the coupon 90 includes circumferential bores for receiving the projections of the adapter plate 591.

[0084] Furthermore, an annular cover plate 593 is provided to press the coupon 90 against the adapter plate 591. In certain embodiments, a fire-retardant material such as wool may be located under the cover plate 593.

[0085] Coupon 90 of the embodiment of Fig. 3 holds a test object 99 in a central area of ​​the coupon 90. The test object 99 extends through the front 91 and the back 92 of the coupon 90, so that the test object 99 comes into contact with both the flame and the airflow 101 and the conditions within the inner channel 102 of the wind tunnel 100 (shown in the Fig. 1 and Fig. 2) is exposed. In other embodiments, the entire coupon 90 is the test item 99. Furthermore, in certain embodiments, the test item 99 is large enough to be used without the adapter assembly in order to fit the test item 99 into the test chamber 500.

[0086] As in Fig. As shown in Figure 3, the test chamber 500 is configured to be attached to the adjacent upstream nozzle 400 and the adjacent downstream channel width adjustment module 600. Specifically, an outer surface of the first wall 401 of module 400 and an outer surface of the first wall 601 of module 600 are configured to engage with an inner surface of the first wall 501; and an outer surface of the second wall 402 of module 400 and an outer surface of the second wall 602 of module 600 are configured to engage with an inner surface of the second wall 502. The inner surfaces of the third walls 403 and 603 of modules 400 and 600 are configured to engage with the third wall 503. and the interior surfaces of the fourth walls 404 and 604 of modules 400 and 600 are configured to engage with the fourth wall 504.

[0087] The channel width adjustment modules 400 and 600 and the ends 505 of the third and fourth walls 503 and 504 form outer annular edges 550 of the test chamber 500. As shown, the modules 400 and 600 can include annular frames 450 and 650 for connection with the outer annular edges 550 of the test chamber 500.

[0088] In addition, flexible channels 300 and 700 are configured to engage with the ring-shaped frames 450 and 650.

[0089] The Fig. show the components from Fig. after assembly. Furthermore, the Fig. , that the test chamber 500 may additionally have flame protection devices 520 on the front of the first wall 501.

[0090] Furthermore, the Fig. 4 and Fig.5, that the duct width adjustment modules 400 and 600 each have opposing curved walls 410 and 610, which cause a gradual change in the depth of the inner duct 102 to prevent turbulent airflow through the test chamber 500. The inner surface 411 of each curved wall 410 is aligned with the inner surface of the respective wall 501 and 502, so that the transition between the curved wall 410 and the walls 501 and 502 is smooth. Likewise, the inner surface 611 of each curved wall 610 is aligned with the inner surface of each respective wall 501 and 502, so that the transition between the curved wall 610 and the walls 501 and 502 is smooth.

[0091] In certain embodiments, the wind tunnel is designed and configured such that a load can be applied via an actuator in the same plane as the test object 99, for example, if the test object 99 has a locking mechanism or other device that may be subjected to a load during flight. The actuator can be attached to the table or the third wall 503 and would exert a vertical / horizontal load (in the direction of flow) on the outside (towards the flame) of the test object 99.

[0092] Although at least one exemplary embodiment has been presented in the foregoing detailed description of the disclosure, it should be noted that there are numerous variations. It should also be noted that the exemplary embodiment or embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description is intended to provide the person skilled in the art with practical guidance for implementing an exemplary embodiment of the disclosure. It is understood that various modifications to the function and arrangement of the elements described in an exemplary embodiment may be made without deviating from the scope of the disclosure as set forth in the appended claims.

Claims

[1] A device for testing flammability, comprising: a wind tunnel consisting of: a test chamber with a first wall and a second wall opposite the first wall, wherein the first wall has a lateral opening; an upstream module located upstream of the test chamber; a downstream module located downstream of the test chamber; an upstream flexible channel connecting the test chamber and the upstream module; and a downstream flexible channel that connects the test chamber and the downstream modules connect each other; a coupon configured to seal the side opening; a fan configured to draw air from the downstream module; a flow restrictor configured to limit the airflow into the upstream module, wherein the fan and the flow restrictor are configured to maintain a selected flow velocity and pressure in the test chamber at the rear of the test piece; a flamethrower configured to direct a flame at the front of the coupon; and a vibration platform configured to provide an excitation input to the test chamber. [2] The device for testing flammability according to claim 1, wherein the coupon comprises or holds a test item which is subjected to a flammability test. [3] The device for testing flammability according to claim 1, wherein the second wall has a transparent window for viewing the reverse side of the coupon. [4] The device for testing flammability according to claim 1, wherein the wind tunnel has an upstream internal height within the upstream module; the wind tunnel has a downstream internal height within the downstream module; the wind tunnel has a test chamber height within the test chamber; and The upstream internal height and the downstream internal height are essentially the same in order to reduce turbulent airflow through the wind tunnel. [5] The device for testing flammability according to claim 1, which further comprises: an upstream channel width adjustment module that connects the upstream flexible channel and the test chamber; and a downstream channel width adjustment module that connects the test chamber and the downstream flexible channel. [6] The device for testing flammability according to claim 1, wherein the upstream module has two interconnected upstream chambers; and The downstream module has two interconnected downstream chambers. [7] The device for testing flammability according to claim 1, which further comprises: a bypass valve formed in the downstream module; and a control module configured to set the fan speed, the throttling range of the flow limiter, and a bypass range of the bypass valve. [8] The device for testing flammability according to claim 1, which further comprises sensors arranged in the test chamber for monitoring temperature and pressure. [9] A method for carrying out a flammability test, wherein the method comprises: Preparing a wind tunnel that features: a test chamber with a first wall and a second wall opposite the first wall, wherein the first wall has a lateral opening; an upstream module arranged upstream of the test chamber; and a downstream module located downstream of the test chamber; Attaching a coupon in the side opening, wherein the coupon has or holds a test item on which the flammability test is carried out, and wherein a reverse side of the coupon is in fluid contact with an interior of the test chamber; Extracting air from the downstream module using a fan; Throttles the airflow in the upstream module with a flow restrictor; and Applying a flame to the front of the coupon. [10] The method according to claim 9, wherein the preparation of the wind tunnel further comprises: Connecting an upstream flexible channel between the test chamber and the upstream module; Connecting a downstream flexible channel between the test chamber and the downstream module; and Applying an excitation input to the test chamber, wherein the upstream flexible channel isolates the upstream module from the excitation input and wherein the downstream flexible channel isolates the downstream module from the excitation input. [11] The method according to claim 10, wherein the preparation of the wind tunnel further comprises: Determining a desired internal width of the test chamber; Assembly of the test chamber with the desired internal width; Connecting the test chamber via the upstream flexible channel to an upstream channel height adjustment module; and Connecting the test chamber via the downstream flexible channel to a downstream channel height adjustment module; the duct height adjustment modules eliminate / reduce turbulent airflows in the test chamber. [12] The method according to claim 9, wherein the downstream module is equipped with a bypass valve and wherein the method further comprises adjusting a fan speed of the fan, a throttling range of the flow limiter and a bypass range of the bypass valve. [13] The method according to claim 9, which further comprises monitoring temperature and pressure with sensors in the test chamber. [14] The method according to claim 9, which further comprises manufacturing the coupon, wherein the side opening has a selected shape and size and wherein the coupon is manufactured with a suitable shape and size to seal the side opening. [15] The method according to claim 9, wherein the test item is an aircraft component. [16] The method according to claim 9, wherein the preparation of the wind tunnel comprises: Providing the upstream module with an upstream internal height; Providing the downstream module with a downstream internal height; and Providing the test chamber with a test internal height; wherein the upstream internal height and the downstream internal height are substantially the same in order to reduce turbulent airflows through the wind tunnel. [17] A method for carrying out a flammability test, wherein the method comprises: Assembling a test chamber with a desired internal width, wherein the test chamber is designed with an opening; Arranging the test chamber on a vibrating platform; Connecting the test chamber to an upstream module via an upstream flexible channel, wherein the upstream module is not located on the vibration platform; Connecting the test chamber to a downstream module via a downstream flexible channel, wherein the downstream module is not located on the vibration platform; Attaching a coupon in the opening, wherein the coupon has or holds a test item on which the flammability test is carried out, and wherein a reverse side of the coupon is in fluid contact with an interior of the test chamber; Extracting air from the downstream module using a fan; Throttles the airflow in the downstream module using a flow restrictor; Applying a flame to the front of the coupon; and Creating an excitation input to the test chamber using the vibrating platform. [18] The method according to claim 17, which further comprises adjusting a fan speed of the fan and a throttling range of the flow restrictor to adjust a pressure in the test chamber. [19] The method according to claim 17, which further comprises monitoring the temperature and pressure with sensors in the test chamber. [20] The method according to claim 17, which further comprises manufacturing the coupon, wherein the opening has a selected shape and size and wherein the coupon is manufactured with a suitable shape and size to seal the opening.

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