CN203083805U

CN203083805U - Near-wall hot-wire probe capable of measuring backflow

Info

Publication number: CN203083805U
Application number: CN 201320039454
Authority: CN
Inventors: 刘涛; 王洪伟
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2013-01-24
Filing date: 2013-01-24
Publication date: 2013-07-24
Anticipated expiration: 2023-01-24

Abstract

The utility model discloses a near-wall hot-wire probe capable of measuring backflows, comprising a probe outer sleeve, a probe inner sleeve, a supporting rod and a hot wire, wherein the probe outer sleeve and the probe inner sleeve are circumferentially positioned, the piston movement can be performed between the probe outer sleeve and the probe inner sleeve, the number of the supporting rods is two, and the supporting rods are arranged along the axis of the probe inner sleeve and are fixed in the probe inner sleeve through insulating materials; and detection ends of the two supporting rods extend out of an opening groove on the top end of the probe outer sleeve, and the hot wire is welded between the probing ends of the two supporting rods. Thus, the probe outer sleeve is fixedly embedded into the side wall of a case of an air compressor, so that the top end surface of the probe outer sleeve is levelled with the near-wall surface of the case, and the distance adjustment between the hot wire and the near-wall surface of the case of the air compressor is realized through the piston movement between the probe outer sleeve and the probe inner sleeve. A baffle block is further arranged between the two supporting rods, so that the projections of the baffle block and the hot wire on the vertical surface are coincided, thereby realizing the backflow measurement. The near-wall hot-wire probe capable of measuring backflows has the advantages that flow fields at different distances from the near wall of the air compressor can measured continuously, the backflows can be measured, and the interference on the flow field is small.

Description

But the nearly wall hot wire probe of survey time stream

Technical field

The utility model relates to a kind of hot wire probe, specifically, is a kind of hot wire probe that the nearly wall of pneumatic plant is measured and refluxed and measure that can be applicable to, and belongs to the turbomachine field.

Background technology

The research end wall regions flows and can improve compressor efficiency, increases its stability.Hot wire probe has less measurement volumes, high frequency sound (good room and time resolution), the passband broad, all very sensitive to Mach number and Reynolds number, be fit to various flow fields, particularly for having shown bigger superiority in low speed flow field and the low Study of Turbulent Flow.So adopting hot wire probe to measure nearly wall flow field tool has great advantage.

Very many about the research work of nearly wall hot-wire measurement both at home and abroad at present, also obtained very many achievements.The nearly wall hot-wire measurement of research both at home and abroad mainly is to use ready-made boundary layer hot wire probe and the MEMS sensor that surperficial hotting mask, Dan Di or Technical Sourcing Internation produce, and these means mainly are to be used for wind tunnel experiment or dull and stereotyped simulated experiment; And the distance that the MEMS sensor that wherein can be applied to the nearly wall measurement of pneumatic plant can not be regulated hot line and wall continuously, and the backflow that can't record the pneumatic plant interior flow field.

The utility model content

In order to solve the problems of the prior art, the utility model proposes a kind of hot wire probe that the nearly wall of pneumatic plant is measured and refluxed and measure that can be used for, comprise cover, pole and heated filament in probe overcoat, the probe.

Wherein, the probe overcoat is a tubular, end sealing, and have pole and pass groove; Cover is tubular in the probe, the coaxial probe overcoat inside that is arranged at, and cover external diameter and probe outer casing internal diameter are complementary in the probe.

The cover internal fixation is filled with insulating material in the above-mentioned probe, axially is set with two poles along cover in the probe in the insulating material; The end of probe of two poles passes groove by the pole on the probe overcoat sealed end and passes; The end of probe of two poles bends in the same way, and is fixed with heated filament between the end of probe of two poles, between two poles insulating spacer is installed also, and insulating spacer is overlapped with the projection of heated filament in perpendicular.

By said structure, the probe overcoat in the hot wire probe can be embedded in the compressor casing sidewall, make the end of probe of pole be positioned at pneumatic plant inside, pass probe by bolt subsequently and put bead outward probe overcoat and pneumatic plant are fixed; Fixedly the time, the sealed end end face that needs to guarantee the probe overcoat flushes with the casing near wall; By the piston motion of cover in the probe, accurately regulate and control the distance between nearly wall heated filament and the nearly wall of pneumatic plant thus with the outer inner room of probe.

Advantage of the present utility model is:

1, the utility model hot wire probe walls such as tip clearance of can be used for measuring pneumatic plant flow, and the distance of hot line and wall can change continuously, and can measure the backflow of pneumatic plant interior flow field;

2, the utility model hot wire probe is in nearly wall measuring process, and whole probe is not in the flow field, has only superfine pole 3 to be in the flow field, and the interference of stream field is very little;

3, the utility model is simple in structure, and is easy for installation, has wide range of applications.

Description of drawings

Fig. 1 the utility model hot wire probe one-piece construction figure;

Fig. 2 the utility model hot wire probe mounting means synoptic diagram.

Among the figure:

Cover 3-pole 4-heated filament in the 1-probe overcoat 2-probe

5-pole passes groove 6-evagination edge 7-block 8-limit sliding chutes

9-pin 10-casing 11-pad 701-sleeve pipe

702-overlaps pipe connected pipe

Embodiment

Below in conjunction with accompanying drawing the utility model is made and to further specify.

But the nearly wall hot wire probe of the utility model survey time stream comprises cover 2, pole 3 and heated filament 4 in probe overcoat 1, the probe, as shown in Figure 1; Wherein, probe overcoat 1 is a tubular, end sealing, and have and be used for the pole that pole 3 passes and pass groove 5; 1 other end of probe overcoat has evagination edge 6, has fixed orifice on the evagination edge 6, passes fixed orifice by bolt, can realize fixing between probe overcoat 1 and compressor casing.Cover 2 is a tubular structure in the probe, coaxial probe overcoat 1 inside that is arranged at, and cover 2 external diameters and probe overcoat 1 internal diameter are complementary in the probe, make interior cover 2 of probe and 1 in probe overcoat can carry out piston motion.

Cover 2 internal fixation are filled with insulating material in the above-mentioned probe, and being provided with 3, two pole 3 spacings of two poles that are parallel to each other along cover 2 axial restraints in the probe in the insulating material is 1.6 ~ 2.0mm.The end of probe of two poles 3 passes groove 5 by the pole on probe overcoat 1 sealed end and passes, and free end stretches out insulating material, is used for connecting follow-up surveying instrument.The end of probe of two poles 3 is bent in the same way, make the vertical range between end of probe end and pole 3 inflection points be about 2mm.Described heated filament 4 is weldingly fixed between the end of probe of two poles 3, is used to measure the flow field; By the piston motion of 1 in cover 2 and probe overcoat in the probe, realize the length adjustment that the heated filament 4 on two poles 3 stretches out probe overcoat 1 thus.

For the backflow that makes the nearly wall hot wire probe of the utility model can record depressor machine internal gas flow, therefore insulating spacer 7 is installed 3 of two poles, insulating spacer 7 is overlapped with the projection of heated filament 4 in perpendicular; The integral structure that insulating spacer 7 is made of two sleeve pipes 701 and cover pipe connections 702 among the present invention, wherein, two sleeve pipes 701 are horizontally disposed with, and two sleeve pipes 701 are by linking to each other formation H type structure with the vertical cover pipe connections 702 of sleeve pipe 701.Two sleeve pipes 701 are enclosed within respectively on two poles 3, and cover pipe connections 702 is overlapped with the projection of heated filament 4 in perpendicular; Thus, when the speed in the flow field was forward, block 7 did not block heated filament 4, made hot wire probe can measure speed in the flow field normally; When the speed in flow field when being reverse, at this moment, 7 pairs of heated filaments 4 of block block, and hot wire probe can not measure the speed in the flow field normally, and on hot wire probe block 7 being installed thus can be so that hot wire probe records the backflow in the flow field.

Above-mentioned probe overcoat 1 side-wall shaft upwards has limit sliding chutes 8, have pilot hole on the cover 2 in the probe, pilot hole is corresponding with limit sliding chutes 8 positions, be fixed in the pilot hole by pin 9 one ends thus, the other end is positioned at chute, can realize 2 piston motion of cover in probe overcoat 1 and the probe spacingly thus, and then limit the length that probe overcoat 1 is stretched out in the detection of two poles 3, from 0.1mm to 10mm, change; Limited circumferential displacement simultaneously to 2 in cover in probe overcoat 1 and the probe.

The utility model hot wire probe is applicable to the nearly wall measurement of pneumatic plant, in implementation process, probe overcoat 1 in the hot wire probe is embedded in the compressor casing sidewall, make the end of probe of pole 3 be positioned at pneumatic plant inside, pass on the probe overcoat 1 bead by bolt subsequently probe overcoat 1 and pneumatic plant are fixed; Fixedly the time, the sealed end end face that needs to guarantee probe overcoat 1 flushes with the casing near wall, therefore can be by regulating at the pad that different-thickness is set between bead on compressor casing outer wall and the probe overcoat 1; Thereby guarantee to have only pole 3 end of probe to be in the pneumatic plant interior flow field, effectively reduce the interference of stream field; By the piston motion of 1 in cover 2 and probe overcoat in the probe, accurately regulate and control the distance between nearly wall heated filament 4 and the nearly wall of pneumatic plant thus.

Claims

1. but the nearly wall hot wire probe of survey time stream comprises cover, pole and heated filament in probe overcoat, the probe; Wherein, the probe overcoat is a tubular, end sealing, and have pole and pass groove; Cover is tubular in the probe, the coaxial probe overcoat inside that is arranged at, and cover external diameter and probe outer casing internal diameter are complementary in the probe;

The cover internal fixation is filled with insulating material in the above-mentioned probe, axially is set with two poles along cover in the probe in the insulating material; The end of probe of two poles passes groove by the pole on the probe overcoat sealed end and passes; The end of probe of two poles bends in the same way, and the end of probe of two poles is welded with heated filament, between two poles insulating spacer is installed also, and insulating spacer is overlapped with the projection of heated filament in perpendicular.

2. but the nearly wall hot wire probe of survey time stream according to claim 1, it is characterized in that: described two distance between tie rods are 1.6～2.0mm.

3. but the nearly wall hot wire probe of survey time stream according to claim 1, it is characterized in that: the end of probe end and the vertical range between the pole inflection point of described two poles are 2mm.

4. but the nearly wall hot wire probe of survey time stream according to claim 1, it is characterized in that: the integral structure that described insulating spacer is made of two sleeve pipes and cover pipe connections, wherein, two sleeve pipes are horizontally disposed with, and two sleeve pipes are by linking to each other with the vertical cover pipe connections of sleeve pipe; Wherein, two sleeve pipes are enclosed within respectively on two poles, and the cover pipe connections is overlapped with the projection of heated filament in perpendicular.

5. but the nearly wall hot wire probe of survey time stream according to claim 1 is characterized in that: described probe sleeve side wall has limit sliding chutes on axially, puts in the probe and has pilot hole, and pilot hole is corresponding with the limit sliding chutes position; Pin one end is fixed in the pilot hole, and the other end is positioned at chute.