JPH05164653A - Fluid pressure loss characteristic simulation structure - Google Patents

Abstract

PURPOSE:To enable pressure loss characteristics to be simulated over a wide range from a laminar flow to a turbulence state by placing a plurality of types of rectification resistors within an enclosure which is fixed to a front edge of a piping coaxially so that it can be inserted and extracted. CONSTITUTION:A cylindrical enclosure 1 is mounted to a front edge of a piping 01 through a flange 2 and an output part fixing orifice 03 is formed at the front edge central part. Honeycomb cores 3 which are made of a plurality of short cylindrical rectification resistors is placed in series in interpolation and with slight gap one another at the enclosure 1, a wire sheet 4 which is an extremely short cylindrical rectification resistor is inserted between the cores 3. a spacer 5 which also plays a role of the rectification resistor is inserted between the last core 3 and a stopper 6, thus enabling the core 3 and the wire sheet 4 to be fixed to the enclosure 1. By selecting a size of a hole of the core 3, a mesh of the wire sheet 4 and the number of it, a thickness of flow direction, order of insertion, etc., pressure loss characteristics can be simulated over a wide range from a laminar flow state to a turbulence state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure loss characteristic simulation structure.

[0002]

2. Description of the Related Art As a fluid pressure loss characteristic simulating structure for measuring the air flow rate, a pressure loss characteristic in an air-conditioning system such as forced cooling of electronic equipment can be substituted at the time of a test or the like. As shown in the longitudinal sectional view, there is known a pipe 01 in which an outlet fixed orifice 03 is attached to a front end of the pipe 01 via a flange 02. 04 here
Is a fluid. Further, as shown in the vertical cross-sectional view of FIG. 6, a pipe 01 is coaxially attached to the front end of the pipe 01 via a flange 05, and an outlet fixing orifice 06 is formed on the front end face thereof. It is known that a case 07 is provided. Here, 08 is a back pressure adjusting plate fixed to the front surface of the housing 07 via bolts 09. In the structure simulation of these structures, in the structure of FIG. 5, the size of the orifice hole of the outlet fixed orifice 03 is selected, and in the structure of FIG. 6, the opening area of the outlet fixed orifice 06 is set to the back pressure adjusting plate. Each adjustment is made by adjusting 08. The pressure loss characteristic at that time is generally obtained by multiplying the density ratio σ = [(fluid density under various conditions) / (reference fluid density)] = (ρ / ρ _STD ) by the pressure loss ΔP, as shown in FIG. 7 line. As shown in the figure, when plotted on a logarithmic graph with the vertical axis and the mass flow rate W on the horizontal axis,
It can be shown by a straight line with a slope of 2.0 in a turbulent flow state where the air flow is sufficient, and with a straight line with a slope of 1.0 in a laminar flow state.

However, in these structures, the normal flow is almost turbulent, and the pressure loss σΔP is proportional to the square of the mass flow rate W. Therefore, the pressure loss σΔP in the fluid passage is about 1 of the mass flow rate W. There is a drawback that only one point can be simulated for the one proportional to the power of 0.2 to 1.8.

[0004]

The present invention has been proposed in view of the above circumstances, and can simulate the pressure loss characteristics over a wide range from a laminar flow state to a turbulent flow state. An object is to provide a fluid pressure loss characteristic simulating structure having excellent properties.

[0005]

To this end, the present invention provides a fluid having a detachable casing coaxially fixed to the front end of a pipe and an outlet fixing orifice formed on the front end face of the casing. In the pressure loss characteristic simulation structure, a plurality of types of rectifying resistors are arranged inside the casing.

[0006]

According to this structure, the following actions are performed. (1) Since the detachable housing fixed coaxially to the front end of the pipe and the outlet fixed orifice formed on the front end surface of the housing are provided, it is possible to simulate a turbulent flow region. become. (2) Since a plurality of types of rectifying resistors are provided inside the casing, the laminar flow region can be simulated by selecting the number and order of them.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described. The same reference numerals as those in FIGS. 5 to 7 represent the same members as those in the drawings. First, in the longitudinal sectional view of FIG.
Is a cylindrical casing attached to the front end of the pipe via a flange 2 and the like, the diameter thereof is the same as that of the pipe 01, and an outlet fixing orifice 03 is formed at the center of the front end face. Reference numeral 3 denotes a honeycomb core which is a plurality of short cylindrical rectifying resistors arranged in a row in the housing 1 so as to be inserted internally and with a slight clearance therebetween, and 4 is inserted between the honeycomb cores 3, respectively. The wire mesh 5, which is an extremely short cylindrical rectifying resistor, fixes the honeycomb cores 3 and the wire meshes 4 to the housing 1, so that between the rearmost honeycomb core 3 and the stopper 6 at the rear end of the housing 1. It is a spacer that is also inserted in and doubles as a rectifying resistor.

In such a structure, the honeycomb core 3
The desired pressure loss characteristics can be obtained by variously selecting the size of the holes, the mesh of the wire mesh 4, the number of each, the thickness in the flow direction, the insertion order, and the like. Further, as shown in the diagram of FIG. 2, the static pressure loss in the static pressure measuring tube (not shown) with respect to the mass flow rate W, that is, the pressure loss ΔP is measured,
By creating the pressure loss characteristic graph, the mass flow rate W can be obtained by measuring the static pressure ΔP _M in the static pressure measurement tube during the test or operation.

Next, a vertical sectional view of FIG. 3 shows a first modified example of FIG. 1, and 7 is a short cylindrical rectifying resistor which is inserted in the housing 1 and is arranged in series at appropriate intervals. A plurality of rectifying pipe groups that are bodies, and 8 are a plurality of perforated plates that are rectifying resistance plates that are appropriately inserted in the front end, the rear end, the central portion, and the like of the housing 1. Even in such a structure, the action and effect are substantially the same as those of the embodiment, and there is a feature that the fine adjustment of the pressure loss characteristic can be easily performed by the back pressure adjusting plate 08.

Further, the vertical sectional view of FIG. 4 shows a second modification of FIG. 1, and 9 is a rectifying duct which is coaxially and detachably attached to the front end of the housing 07 and which has an appropriate length. Its diameter is substantially the same as that of the pipe 01, and inside it is a honeycomb core 3, a wire net 4, a spacer 5, and a perforated plate 8.
Etc. are appropriately arranged. Reference numeral 10 is a static pressure measuring tube that is provided so as to project from the housing 07. Even in such a structure,
The action and effect are substantially the same as those of the embodiment, and since the diameter of the casing 07 is about 3 times that of the pipe 01,
It has features that make it suitable for relatively large simulation devices.

According to the structures of these embodiments and modifications,
The following effects are exhibited. (1) Since a detachable housing fixed coaxially to the front end of the pipe and an outlet fixed orifice formed on the front end surface of the housing are provided, a turbulent flow region can be simulated.
Therefore, it is possible to satisfy one condition of the simulated structure. (2) Since a plurality of types of rectifying resistors are provided inside the casing, the laminar flow region can be simulated by selecting the number and order of them, and therefore the other condition of the simulated structure can be provided. Becomes (3) With the cooperation of the above (1) and (2), each flow state can be simulated, and thus the practicality of the simulated structure is improved.

[0012]

In summary, according to the present invention, a fluid pressure loss characteristic having a detachable casing coaxially fixed to the front end of the pipe and an outlet fixed orifice formed on the front end face of the casing. By arranging multiple types of rectifying resistors inside the casing in the simulated structure, it is possible to simulate the pressure loss characteristics over a wide range from the laminar flow state to the turbulent flow state, and therefore it is excellent in practicality. The present invention is extremely useful industrially because a fluid pressure loss characteristic simulating structure is obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram for obtaining a mass flow rate from the pressure loss measured by the structure of FIG.

FIG. 3 is a vertical sectional view of the first modification of FIG.

FIG. 4 is a vertical sectional view of the second modification of FIG.

FIG. 5 is a vertical cross-sectional view showing a known fluid pressure loss characteristic simulating structure.

FIG. 6 is a vertical sectional view showing a known fluid pressure loss characteristic simulating structure different from that of FIG. 5;

7 is a diagram showing the relationship between pressure loss and mass flow rate in the structures of FIGS. 5 and 6. FIG.

[Explanation of symbols]

 1 Case 2 Flange 3 Honeycomb Core 4 Wire Mesh 5 Spacer 6 Stopper 7 Rectification Pipe Group 8 Perforated Plate 9 Rectification Duct 10 Static Pressure Measurement Tube 01 Piping 02 Fixed Olihus at Exit 03 Fixed Olihus 04 Fluid 07 Casing 08 Back Pressure Adjustment Board

Claims (1)

[Claims] 1. A fluid pressure loss characteristic simulating structure comprising a detachable casing coaxially fixed to a front end of a pipe and an outlet fixed orifice formed on the front end face of the casing, wherein the casing is A fluid pressure loss characteristic simulating structure characterized by arranging multiple types of rectifying resistors inside the.