JPH0658284B2 - Environmental wind tunnel for automobiles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wind tunnel, and more particularly to a wind tunnel suitable for use in an environmental test of an automobile.

[Conventional technology]

Conventionally, an open type in which an object to be measured is placed in a free jet or a closed type in which an object to be measured is placed in a duct has been used as a measuring portion of a wind tunnel used for measuring air resistance of an aircraft, an automobile, and the like. For example, the above-mentioned conventional wind tunnel technology is discussed in "Fluid Mechanics Experimental Method" edited by Ichiro Tani, pp. 1977-1228, published by Iwanami Shoten.

[Problems to be solved by the invention]

Even in the above-mentioned conventional type, in order to bring the flow around the measuring object close to the actual state, it is necessary to make the cross-sectional area of the air flow several times larger than that of the measuring object. Moreover, the air flow temperature is set to -40 ° C to -5.
In an environmental wind tunnel for automobiles where the temperature is lowered to 0 ° C and an air conditioning performance test is performed in an extremely cold region with an actual vehicle, a blower for air flow drive and a refrigerator for lowering the air flow are required, so operation of equipment is downsized and energy saving is performed. To reduce the cost, it is necessary to make the air flow cross section as small as possible.

An object of the present invention is to provide an environmental wind tunnel for automobiles that can be tested with a small air flow cross-sectional area.

[Means for solving problems]

The above-mentioned problems are environmental wind tunnels for automobiles that include a wall surface that is arranged so as to surround the vehicle under test, an opening for introducing an air flow into the vehicle under test, and an opening for discharging the air flow passing around the vehicle under test. In the above, the problem is solved by making the shape of the wall surface into a running state of the vehicle under test or a streamlined shape that can simulate the running state.

[Action]

If a duct with the shape of a streamline formed when an object is placed in a uniform flow is installed around the object and the flow is made to flow inside the duct, the flow around the object will be a uniform flow due to the definition of the streamline. It is almost the same as the case in. The present invention utilizes this phenomenon to reproduce the flow when an object is uniformly placed with a small flow rate in the duct. Also, the streamlines around an object placed in a uniform flow are almost the same at an appropriate distance (eg, typical dimensions) from the object if the shape and size of the object are similar, so prepare a small number of ducts. It is possible to reproduce the flow around many objects with similar shapes and dimensions by simply doing.
A large number of openings are provided on the wall surface of the duct to allow airflow in and out, and the duct restrains the force that restricts the flow to reproduce the flow around an object of a wide range of shapes and sizes. Further, the flow is sucked in or sucked out through the opening to accurately reproduce the state of the flow around the object having a wider range of shapes and sizes.

The above concept is not suitable when accurate values of resistance and pressure distribution of an object placed in uniform Ryu are required,
In the case of an environmental wind tunnel for automobiles, it suffices if the pressure distribution around the object can be reproduced within a range where environmental experiments can be performed. Therefore, the wind tunnel test can be performed with a small air flow by using the concept described above.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a test vehicle, 2 is an airflow flowing into the measuring section, 3 is a streamlined curved surface cover, 4 is a floor surface and at the same time forms a wall surface of the measuring section. As shown in FIG. 2, the curved line 3 of the curved surface cover 3 approximates a streamline 3'obtained by a wind tunnel test in which the vehicle under test 1 can accurately simulate a running state or a running state, and further by a flow analysis. The curved surface of the cover 3 is three-dimensionally and substantially along the streamline, as shown in FIG. 3 which shows the S-S 'cross section of FIG. 1 and FIG. 4 which shows the TT' cross section of FIG. . Since the wind tunnel of the present invention is configured in this way, the test vehicle 1 is placed in a uniform flow even if the cross-sectional area of the air flow 2 flowing into the measurement section is about the same as the cross-sectional area of the test vehicle 1. it can. If the shape and size of the vehicle under test are similar to 1 such as 1 ', the shape of the streamline obtained by placing the vehicle under test 1'in a uniform stream and the shape of the streamline obtained by placing the vehicle under test 1 in a uniform stream are obtained. The shape of the streamline is almost the same except near the vehicle under test. Therefore, the curved surface cover 3 manufactured according to the test vehicle 1 can be used for the test vehicle 1 '.

5 and 6 show the case where the curved cover 3 is provided with a large number of openings 6. Since the flow can pass through the opening 6 as shown by the arrow 7, the same curved cover 3 can be used even if the shape of the vehicle under test changes greatly as shown in FIG.

8 and 9 show an embodiment in which the balance chamber 8 is provided outside the curved surface cover 3. Since the flow 9 entering the balance chamber 8 surely returns like the flow 10, good results can be obtained even in the case where the test vehicle 1 is large and the gap with the curved surface cover 3 is small.

FIG. 10 shows that the balance chamber 8 of the embodiment shown in FIGS. 8 and 9 is provided with a passage 11 to the outside, and the flow is sucked to the outside through the passage 11 or the flow is supplied from the outside to make the test vehicle 1 This is a case where the surrounding flow is actively controlled.

FIG. 11 shows the case where the balance chambers 8 are provided on the left and right sides, and the passages 11 to the outside are provided in each of them. In this case, when the flow is supplied to one of the balance chambers and sucked from the other, it is possible to simulate the case where the flow of the lateral component is added to the flow of the vehicle 2 from the front as shown in the figure.

In the embodiment shown in FIGS. 12 and 13, the balance chamber is divided into a large number of passages, and a passage 11 is provided in each chamber.
2 is provided to suck the boundary layer that develops on the floor surface 4, and the collecting chamber 13 and the passage 14 are installed. In the case of this real gun example, the flow around the sample vehicle 1 can be adjusted to the actual state with high accuracy by controlling the supply / exhaust amount to each balance chamber and the suction of the floor boundary layer.

〔The invention's effect〕

According to the present invention, it is possible to realize a flow around a test vehicle placed in a uniform flow with a small air flow cross-sectional area, so that it is possible to greatly reduce the size of an environmental wind tunnel and reduce operating costs.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an automobile environmental wind tunnel of the present invention, FIG. 2 is a view showing streamlines around a test vehicle, and FIG. 3 is S- of FIG.
A sectional view taken along the line S ', FIG. 4 is a sectional view taken along the line TT' in FIG. 1, and FIGS. 5 to 13 are views showing other embodiments.
Figure, Figure 8, Figure 10, Figure 12 are longitudinal sectional views, Figure 6,
FIG. 9, FIG. 11 and FIG. 13 are transverse sectional views. 1 ... Test vehicle, 3 ... curved surface cover, 4 ... floor surface, 6 ...
Opening, 8 ... Balance room, 11 ... Passage, 13 ... Assembly room, 14 ... Passage.

Claims (5)

[Claims] 1. A vehicle environment comprising a wall surface arranged so as to surround a vehicle under test, an opening for introducing an air flow into the vehicle under test, and an opening for discharging an air flow passing around the vehicle under test. In the wind tunnel, an environmental wind tunnel for automobiles, characterized in that the shape of the wall surface is a streamlined shape that can simulate the running state or running state of the test vehicle. 2. An environmental wind tunnel for an automobile according to claim 1, wherein a large number of openings are provided in a part of the wall surface. 3. An environmental wind tunnel for an automobile according to claim 2, wherein a balance chamber connected to the outside only through the openings is provided outside the wall surface provided with a large number of openings. 4. An environmental wind tunnel for an automobile according to claim 3, wherein the balance chamber is provided with a passage other than an opening provided on the wall surface of the wind tunnel to supply or suck the air flow from the outside. 5. The balance chamber according to claim 4, wherein the balance chamber is divided into two or more partitions, and each chamber is provided with a passage to the outside other than an opening provided in the wall surface of the wind tunnel to supply an airflow from the outside. Or an environmental wind tunnel for automobiles, which is characterized by sucking an airflow to the outside.