JPS59141031A - Flow visualizing apparatus for wind-tunnel - Google Patents

Abstract

PURPOSE:To make it possible to stably supply a large amount of smoke and to control the whole amount to be generated of the smoke, by providing a smoke generating part equipped with a plurality of smoke generating chambers, a plurality of smoke jet nozzles and a smoke stream generating part. CONSTITUTION:A smoke generating part 4 is divided into a plurality of smoke generating chambers 11 and this apparatus has a smoke stream generating part 6 constituted of a plurality of smoke jet nozzles 5 and a nozzle base 9 which holds the smoke jet nozzles 5 and a predetermined position and introduces the smoke supplied from the smoke generating part 4 through a smoke conduit 8 while classifying the same. By this constitution, a large amount of smoke can be stably supplied and the whole amount to be generated of the smoke can be controlled.

Description

[Detailed description of the invention] (Technical field of 81 inventions The present invention relates to a wind tunnel device for observing fluid flow.

More specifically, the present invention relates to an improvement of the flow visualization means.

(bl Technology background Place the object to be measured into the fluid flow.

The state of the flow that occurs around the object 9 For example, by understanding the stream line that indicates the direction of the flow, the flow velocity that can be calculated from its temporal change, or the pattern of vortex generation, determine the object in the fluid. In the past, it has been widely practiced to accumulate fluid dynamic data for use as design materials.

Various methods related to flow visualization have been developed and used as powerful means for the above-mentioned flow observation.

(C1 Prior Art and Problems) One of the above-mentioned flow visualization methods is to directly mix a tracer substance that serves as a flow mark into the fluid in order to visually observe the flow itself, and to know the pattern of the flow from the lines drawn by the tracer substance. This method further includes a direct injection method in which a different substance is mixed with the fluid, and a method in which the fluid itself is used as a tracer by utilizing chemical or electrochemical changes in the fluid.

The direct injection method is a tracer method in a narrow sense and has been used for a long time.
It is important that it is mixed into the flow in a controlled manner.

As tracer substances, cigarette and incense smoke are suitable for observing medium-low velocity gases, and 1 Parsan fume incense smoke is used for high-speed airflow. Large diameter mist of tracer substance particles (
For the droplet method, famous tracer substances include kerosene, liquid paraffin, dry ice, and titanium tetrachloride.

Among these visualization means, an example of a wind tunnel apparatus equipped with a smoke flow generating section using smoke as a tracer substance is shown in the perspective view of FIG.

The air intake port 1 is equipped with a rectifier grid 1a or a flow rectifier network, and has the function of adjusting the introduced fluid to form a laminar flow. The flow is restricted and connected to the measuring section 3. Connected to the contraction section 2.

In order to receive smoke continuously or intermittently from the smoke generating part 4 and draw smoke streamlines in the measuring part 3, the smoke flow generation device is equipped with a plurality of smoke volume ejection nozzles 5 on a plane parallel to the measuring surface. A section 6 is provided. The measuring section 3 is provided with an observation window made of a transparent material on its front side, and its back wall is made of a dark color and non-reflective surface to facilitate observation and photography of smoke flow.

Furthermore, an exhaust means 7 having a sufficient capacity to obtain an airflow at a predetermined flow rate is provided.

Now, the wind tunnel equipment mentioned above is used to observe patterns of changes in airflow due to the object being measured.

The airflow that blows onto the object must be a laminar flow without turbulence. As is clear from FIG. 1, the smoke flow generating section 6
Since it exists in the middle of the airflow, it has a streamlined shape so as not to disturb the airflow, including the smoke output nozzle 5. FIG. 2 is a perspective view showing the structure of the smoke flow generating section 6. As shown in FIG.

The smoke generated in the smoke generating section 4 passes through the smoke introduction pipe 8 and is sent upward and downward into two directions.
The smoke reaches the smoke output nozzle 5 through the smoke path 10 in the nozzle base 9, which is formed by dividing and machining the parts into one body, and is continuously injected into the air stream from there.

The above-mentioned smoke generating section 4 is usually a rectangular parallelepiped metal box in which a bundle of incense sticks or a bundle of cigarettes is stored as a smoke source.

It burns at an appropriate temperature and produces smoke. Incense sticks and cigarette smoke have small particle sizes and are well-aligned.

It is especially suitable for observing patterns in low-velocity fluids.

The number of incense sticks and cigarettes is adjusted according to the amount of smoke required, and they are lit at the same time, and the smoke is sent to the smoke flow generating section 6 using a blower (not shown).

In order to generate smoke efficiently, it is necessary to maintain an appropriate combustion temperature depending on the smoke source. However, when a large amount of smoke is required and a large amount of incense etc. is burned, the temperature gradually rises due to the combustion heat of the smoke source such as the incense stick, the combustion speed becomes faster, the combustion state approaches complete combustion, and the amount of smoke generated decreases. It will decrease.

To counter this problem, some kind of improvement has been required for the smoke generating section 4, which is the combustion chamber that is the source of smoke.

(d) Purpose of the Invention The present invention has been made in view of the above-mentioned points.
The purpose of this invention is to provide a smoke generating section with a structure that allows the amount of smoke generated to be increased to a required amount.

le) Structure of the Invention The object of the above invention is to provide a wind tunnel device for observing fluid flow having a flow visualization device using smoke as a tracer substance.
A smoke generating section including a plurality of smoke generating chambers, a plurality of smoke output nozzles, and a smoke generating section that holds the smoke output nozzles in a predetermined position and that emits smoke supplied from the smoke generating section through a smoke conduit. This can be easily achieved by a flow visualization device for a wind tunnel, which is characterized by having a smoke flow generating section that includes a nozzle base that branches into the nozzle.

(fl Embodiments of the Invention Examples of the present invention will be described below with reference to the drawings. FIG. 3 is a perspective view showing the structure of an embodiment of the smoke generating section 4 of the flow visualization device for a wind tunnel based on the present invention. be.

The smoke generating section 4 is divided into a plurality of smoke generating chambers 11 as shown. In the case of this example, it is composed of six rooms,
Bunches of cigarettes 12 are stored in two tiers in each room. Depending on the overall amount of smoke, the amount of smoke is adjusted by using all six rooms or using just a portion of them.

As mentioned above, in order to prevent the temperature of the bundle of cigarettes 12 that is the smoke source from rising excessively and to release part of the combustion heat to the outside, the partition wall 14 of each smoke generation chamber 11 of the smoke generation section 4 is provided with a Use a relatively thick metal plate.

The generated smoke is sent to the smoke flow generation section 6 by the fan 13 of the smoke generation section 4.

FIG. 4 is a perspective view showing a modification of the embodiment of the smoke generating section 4 shown in FIG.
Although this example is equipped with the following, the principle is the same.

(gl) Effects of the Invention As is clear from the above explanation, by equipping a wind tunnel flow visualization device that uses smoke as a tracer with the smoke generation details according to the present invention, a large amount of smoke can be stably supplied, and
This has the effect of being able to control the overall amount of smoke generated and making it possible to observe the flow pattern in a wind tunnel over a wide range.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a wind tunnel apparatus equipped with a smoke flow generation section using smoke as a tracer substance, FIG. 2 is a perspective view showing the configuration of the smoke flow generation section 6, and FIG. 3 is based on the present invention. FIG. 4 is a perspective view showing the configuration of an embodiment of the smoke generating section of the flow visualization device for a wind tunnel; FIG. 4 is a perspective view showing a modification of the embodiment of the smoke generating section shown in FIG. 3; In the figure, 1 is the air intake port, and 2 is the contraction part. 3 is a measurement part, 4 is a smoke generation part, 5 is a smoke blowing nozzle, 6
1 is a smoke flow generation section, 7 is an exhaust means, 8 is a smoke introduction pipe, 9 is a nozzle base, 10 is a smoke path, and 11 is a smoke generation chamber. 12 represents a bundle of cigarettes, and 13 represents a fan. Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] In a wind tunnel device for observing fluid flow having a flow visualization device using smoke as a tracer substance, a smoke generation section having a plurality of smoke generation chambers, a plurality of smoke ejection nozzles, and holding the smoke ejection nozzles in a predetermined position. A flow visualization device for a wind tunnel, characterized in that the smoke flow visualization device includes a smoke flow generation section including a nozzle base for branching and introducing smoke supplied from the smoke generation section to the nozzle via a smoke conduit.