JPH0658304B2 - Vehicle air resistance measuring device - Google Patents
Vehicle air resistance measuring deviceInfo
- Publication number
- JPH0658304B2 JPH0658304B2 JP61164396A JP16439686A JPH0658304B2 JP H0658304 B2 JPH0658304 B2 JP H0658304B2 JP 61164396 A JP61164396 A JP 61164396A JP 16439686 A JP16439686 A JP 16439686A JP H0658304 B2 JPH0658304 B2 JP H0658304B2
- Authority
- JP
- Japan
- Prior art keywords
- vehicle body
- total pressure
- vehicle
- air resistance
- measuring means
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、車両の空気抵抗測定装置に関するものであ
る。The present invention relates to a vehicle air resistance measuring device.
（従来の技術） 従来より車両、特に自動車の車体表面の空気流れの測定
は、煙を利用し、該煙を車体前面部より後部方向に所定
の流速で流して見てその流線の変化をストロボ等を利用
して観測する構成を採るのが一般的である(例えば実開
昭６０−４２９３９号公報参照)。(Prior Art) Conventionally, the measurement of the air flow on the surface of the vehicle body of a vehicle, particularly an automobile, utilizes smoke, and changes in the streamline are observed by flowing the smoke from the front surface of the vehicle body toward a rear portion at a predetermined flow velocity. It is common to adopt a configuration of observing using a strobe or the like (see, for example, Japanese Utility Model Laid-Open No. 60-42939).
（発明が解決しようとする問題点） ところが、上記従来技術の構成では車体表面が滑らかに
起伏変化する部分では比較的流線が明瞭で観測も容易で
あるが、例えば車体底面部のように各種自動車部品、付
属装置等の存在により起伏部の多い部分の空気抵抗を該
部分の空気流れの変化により測定するような場合には、
当該起伏部で生じる空気流の剥離や乱流のために煙の流
線が乱れて殆んど観測不能となってしまう問題がある。(Problems to be Solved by the Invention) However, in the configuration of the above-mentioned conventional technique, streamlines are relatively clear and easy to observe at a portion where the vehicle body surface smoothly undulates and changes. When measuring the air resistance of a part with many undulations due to the presence of automobile parts, auxiliary equipment, etc., by changing the air flow in that part,
There is a problem that the streamlines of smoke are disturbed by the separation and turbulence of the airflow generated at the undulations, making it almost unobservable.
従って、上記流れ場における煙の流線の変化から当該自
動車の車体位置に対応した空気抵抗の分布状態やその大
きさ等を分析判断しようとしても実際上正確な判定はで
きないことになる。Therefore, even if an attempt is made to analyze and determine the distribution state of air resistance corresponding to the vehicle body position and the size thereof from the change of smoke streamlines in the flow field, it is not possible to make an accurate determination in practice.
（問題点を解決するための手段） 本発明は、上記の問題点を解決することを目的としてな
されたもので、車体外表面の空気流の総圧を測定する車
幅方向に並列配置された複数の圧力センサよりなる総圧
測定手段と、該総圧測定手段を車体外表面に沿って、か
つ車体前後方向に移動するトラバース手段とを備え、上
記総圧測定手段を上記トラバース手段により車体外表面
に沿って車体前後方向に移動させることにより車体外部
形状に対応して車体の空気抵抗を測定するようにしてな
るものである。(Means for Solving Problems) The present invention has been made for the purpose of solving the above problems, and is arranged in parallel in the vehicle width direction for measuring the total pressure of the air flow on the outer surface of the vehicle body. The total pressure measuring means including a plurality of pressure sensors and the traverse means for moving the total pressure measuring means along the outer surface of the vehicle body and in the front-rear direction of the vehicle body are provided outside the vehicle body by the traverse means. By moving the front-rear direction of the vehicle body along the surface, the air resistance of the vehicle body is measured in accordance with the external shape of the vehicle body.
（作 用） 上記の手段によると、車両の車体外表面の空気流の総圧
を測定する総圧測定手段が、トラバース手段によって当
該車体の外部形状に応じて、しかも車体前後方向に自由
移動されるようになっているから、車体外部形状に応じ
て変化する実際の空気流に対応して当該各変化位置の各
々の部位で当該空気流の総圧から空気抵抗を容易かつ正
確に測定することができるようになる。(Operation) According to the above means, the total pressure measuring means for measuring the total pressure of the air flow on the outer surface of the vehicle body of the vehicle is freely moved by the traverse means according to the external shape of the vehicle body and further in the longitudinal direction of the vehicle body. Therefore, it is possible to easily and accurately measure the air resistance from the total pressure of the air flow at each position of each change position corresponding to the actual air flow that changes according to the external shape of the vehicle body. Will be able to.
（実施例） 第１図〜第３図は、本発明の実施例に係る車両の空気抵
抗測定装置を示している。(Embodiment) FIGS. 1 to 3 show a vehicle air resistance measuring device according to an embodiment of the present invention.
先ず第１図において、符号１はファンダクトＦを有する
風洞試験室２内に納入設置された空気抵抗測定対象とし
ての車両(自動車)であり、該車両１の下方には総圧測定
手段１０を支持したトラバース手段２０が設置されてい
る。このトラバース手段２０は、昇降装置２０Ａと水平
移動装置２０Ｂとから構成されている。First, in FIG. 1, reference numeral 1 is a vehicle (automobile) as an air resistance measurement target that is delivered and installed in a wind tunnel test chamber 2 having a fan duct F, and a total pressure measuring means 10 is provided below the vehicle 1. A supported traverse means 20 is installed. The traverse means 20 is composed of a lifting device 20A and a horizontal moving device 20B.
先ず上記総圧測定手段１０は、例えば第２図に示すよう
に、車幅方向に複数本並列配置された総圧管(特許請求
の範囲中の圧力センサに当該する)１１，１１・・と、
これら複数本の総圧管１１，１１・・を上記並列状態で
車幅方向に支持した支持部材１２とから構成されてい
る。また、トラバース手段２０を構成する昇降装置２０
Ａは、上記総圧測定手段１０の上記支持部材１２をその
両端部で上下移動可能に螺合支持した螺溝を有する第１
および第２のスクリュー軸１３a,１３bと、該第１およ
び第２のスクリュー軸１３a,１３bを立設支持した車幅
方向に延びる支持板１４と、上記第１および第２のスク
リュー軸１３a,１３bの一方側第１のスクリュー軸１３a
の基部に設けられた当該一方側の第１のスクリュー軸１
３aを任意に回動させる第１のパルスモータ１５と、こ
の第１のパルスモータ１５の駆動軸１５aに設けられた
駆動側タイミングプーリ１６と上記他方側第２のスクリ
ュー軸１３bに設けられた従動側タイミングプーリ１７
との間に掛け渡され上記両スクリュー軸１３a,１３bを
回動させる第１のタイミングベルト１８とからなり、上
記総圧測定手段１０の総圧管１１，１１・・を支持した
支持部材１２は上記第１のパルスモータ１５の回転量に
応じて上記両スクリュー軸１３a,１３bの上下方向に任
意に昇降移動されるようになっている。上記第１のパル
スモータ１５の回転時期と回転量は、後述するトラバー
スコントロールユニット４０により上記車両１の底面形
状に応じて制御される。First, the total pressure measuring means 10 includes, for example, as shown in FIG. 2, a plurality of total pressure pipes (corresponding to a pressure sensor in claims) 11, 11 ...
.. and a support member 12 that supports the plurality of total pressure pipes 11, 11 ... In the vehicle width direction in the parallel state. Further, the lifting device 20 that constitutes the traverse means 20.
A is a first groove having a screw groove in which the supporting member 12 of the total pressure measuring means 10 is screwed and supported at both ends thereof so as to be vertically movable.
And second screw shafts 13a, 13b, a support plate 14 extending in the vehicle width direction that supports the first and second screw shafts 13a, 13b upright, and the first and second screw shafts 13a, 13b. One side first screw shaft 13a
The one side first screw shaft 1 provided at the base of the
3a, a first pulse motor 15 that rotates arbitrarily, a drive-side timing pulley 16 provided on a drive shaft 15a of the first pulse motor 15, and a follower provided on the second screw shaft 13b on the other side. Side timing pulley 17
And a first timing belt 18 that rotates between both screw shafts 13a and 13b and that supports the total pressure pipes 11, 11, ... According to the rotation amount of the first pulse motor 15, the two screw shafts 13a and 13b can be arbitrarily moved up and down. The rotation timing and the rotation amount of the first pulse motor 15 are controlled by a traverse control unit 40 described later according to the shape of the bottom surface of the vehicle 1.
また、上記水平移動装置２０Ｂは、上記総圧測定手段１
０の支持板１４の両端部１４a,１４bを車体前後方向に
移動可能に支持する第３および第４のスクリュー軸２１
a,２１bと、この第３および第４のスクリュー軸２１a,
２１bを回動可能に支持する支持部材２２a,２２bと、上
記第３および第４のスクリュー軸２１a,２１bの一方側
の第３のスクリュー軸２１aの一端側基部に設けられた
第２のパルスモータ２３と、この第２のパルスモータ２
３の駆動側タイミングプーリー２３aと上記他方側第４
のスクリュー軸２１bの従動側タイミングプーリー２３b
との間に掛け渡された第２のタイミングベルト２５とか
ら構成されている。そして、上記第２のパルスモータ２
３の回転によって上記第３および第４のスクリュー軸２
１a,２１bが回動せしめられることにより、上記総圧測
定手段１０が当該各スクリュー軸２１a,２１bに沿って
車体前後方向に移動せしめられる。Further, the horizontal moving device 20B is the total pressure measuring means 1 described above.
Third and fourth screw shafts 21 for movably supporting both ends 14a, 14b of the support plate 14 of 0 in the vehicle longitudinal direction.
a, 21b, and the third and fourth screw shafts 21a,
21b for rotatably supporting 21b, and a second pulse motor provided at one end side base of the third screw shaft 21a on one side of the third and fourth screw shafts 21a, 21b. 23 and this second pulse motor 2
No. 3 drive side timing pulley 23a and the other side fourth
Timing pulley 23b on the driven side of the screw shaft 21b
It is composed of a second timing belt 25 that is stretched between and. Then, the second pulse motor 2
3 rotation of the third and fourth screw shafts 2
By rotating 1a and 21b, the total pressure measuring means 10 is moved in the vehicle front-rear direction along the screw shafts 21a and 21b.
上記第２のパルスモータ２３の回転時期と回転量も、ま
た上記第１のパルスモータ１５の場合と同様にトラバー
スコントロールユニット４０により上記車両１の下面形
状に対応してコントロールされる。The rotation timing and the rotation amount of the second pulse motor 23 are also controlled by the traverse control unit 40 in accordance with the shape of the lower surface of the vehicle 1 as in the case of the first pulse motor 15.
このトラバースコントロールユニット４０は、例えばマ
イクロコンピュータにより構成されていて、上記空気抵
抗の測定対象となる上記車両１下面の形状に応じて上記
総圧測定手段１０を車体上下方向および車体前後方向に
任意に駆動制御するために当該車両の車体外部形状に応
じたマップデータメモリを備えて構成されている。The traverse control unit 40 is composed of, for example, a microcomputer, and the total pressure measuring means 10 is arbitrarily arranged in the vehicle body vertical direction and the vehicle body front-back direction according to the shape of the lower surface of the vehicle 1 which is the measurement target of the air resistance. A map data memory corresponding to the external shape of the vehicle body of the vehicle is provided for drive control.
一方、上記トラバース手段２０によって上述のごとく車
両上下および前後方向に任意に移動可能となった上記総
圧測定手段１０の総圧管１１，１１・・は、第３図に示
すように、先端が外方に向けて拡大された空気取入口１
１０を有する略流れに平行な大径の管体１１１と、該管
体１１１の内部に後方より挿入された圧力取入れ用の小
径の連通パイプ１１２とからなり、該連通パイプ１１２
の圧力(動圧と静圧との和となる)をスキャニングバルブ
１１４を介して例えばパーソナルコンピュータ５２を組
合せた空気抵抗計測装置５０の演算部５１に入力する。
また、この入力時に当該流れ場における基準ピトー管１
１６の検出圧(無次元化した背圧)も同時に入力される。On the other hand, as shown in FIG. 3, the total pressure pipes 11, 11, ... Of the total pressure measuring means 10, which can be arbitrarily moved in the vertical and longitudinal directions of the vehicle by the traverse means 20, have outer ends as shown in FIG. Air intake 1 expanded towards
A large-diameter pipe body 111 having a substantially parallel flow and a small-diameter communication pipe 112 for inserting pressure, which is inserted into the interior of the pipe body 111 from the rear side.
The pressure (which is the sum of the dynamic pressure and the static pressure) is input to the calculation unit 51 of the air resistance measuring device 50 in which the personal computer 52 is combined, for example, via the scanning valve 114.
Also, at the time of this input, the reference Pitot tube 1 in the flow field concerned
The 16 detection pressures (dimensionless back pressure) are also input at the same time.
上記空気抵抗計測装置５０の演算部５１では、上記各入
力を基に所定の演算動作を行って実際の総圧を測定す
る。The arithmetic unit 51 of the air resistance measuring device 50 performs a predetermined arithmetic operation based on each of the above inputs to measure the actual total pressure.
従って、以上の構成によると、上記トラバースコントロ
ールユニット４０により上記第１、第２のパルスモータ
１５，２３を駆動して例えば第４図に示すような車両１
の車体下面形状に応じて例えば同第４図に仮想線Ｘで示
すように車体前方から後方に総圧測定手段１０を移動さ
せることにより、当該車体下面各部(イ)〜(ヘ)の空気流
の総圧を上記空気抵抗計測装置５０により測定し、それ
を例えばグラフィックディスプレイ機能を備えたパーソ
ナルコンピュータ５２でパターン表示すると例えば第６
図(a)のようになる。この第６図(a)は、結局上記車体の
底面形状に応じた空気流の変化による総圧分布状態を示
しており、該パターンを説明を簡単にするために単純に
２次元化してその総圧係数Ｃptの変化として示すと第５
図のようになる。この第５図は、上記第４図の(イ)〜
(ヘ)の各車体下面位置に対応させて総圧係数Ｃptの変化
を示したものである。Therefore, according to the above configuration, the traverse control unit 40 drives the first and second pulse motors 15 and 23 to drive the vehicle 1 as shown in FIG. 4, for example.
By moving the total pressure measuring means 10 from the front side to the rear side of the vehicle body in accordance with the shape of the vehicle body lower surface of FIG. Is measured by the air resistance measuring device 50 and is displayed as a pattern on the personal computer 52 having a graphic display function.
It looks like Figure (a). FIG. 6 (a) shows the total pressure distribution state due to the change of the air flow according to the bottom shape of the vehicle body, and the pattern is simply made into two dimensions to simplify the explanation. It is the fifth when shown as the change of the pressure coefficient Cpt.
It becomes like the figure. This FIG. 5 shows (a) to FIG.
(F) shows changes in the total pressure coefficient Cpt corresponding to the vehicle body bottom surface positions.
第５図を見ると、総圧係数Ｃptが低下し始める位置Ｘ1,
Ｘ2点より少し前方(Ｘ＜Ｘ1,Ｘ＜Ｘ2)に各々の剥離点Ｘ
a1,Ｘa2があると考えられる。そして、結局この剥離点
Ｘa1,Ｘa2より総圧損失ΔＣpt1,ΔＣpt2が生じると考え
られる。従って、以上のパターンより全体の総圧変化パ
ターンを解析して、上記総圧損失の始まる部分の形状を
修正して空気抵抗を小さくすると、上記総圧分布は第６
図(b)のように変化し、空気抵抗の小さい車体構造にす
ることができることが明らかとなる。Referring to FIG. 5, the position X 1 at which the total pressure coefficient Cpt starts to decrease,
A little in front of the X 2 point (X <X 1 , X <X 2 ) at each peeling point X
It is considered that there are a 1 and Xa 2 . Then, it is considered that the total pressure losses ΔCpt 1 and ΔCpt 2 are eventually generated from the separation points Xa 1 and Xa 2 . Therefore, if the total pressure change pattern of the entire pattern is analyzed and the shape of the portion where the total pressure loss starts is corrected to reduce the air resistance, the total pressure distribution becomes the sixth pattern.
It is clear that the vehicle structure can be changed as shown in Fig. (B) to have low air resistance.
（発明の効果） 本発明は、以上に説明したように、車体外表面の空気流
の総圧を測定する車幅方向に並列配置された複数の圧力
センサよりなる総圧測定手段と、該総圧測定手段を車体
外表面に沿って、かつ車体前後方向に移動するトラバー
ス手段とを備え、上記総圧測定手段を上記トラバース手
段により車体外表面に沿って車体前後方向に移動させる
ことにより車体外部形状に対応して車体の空気抵抗を測
定するようにしたことを特徴とするものである。(Effects of the Invention) As described above, the present invention provides a total pressure measuring unit including a plurality of pressure sensors arranged in parallel in the vehicle width direction for measuring the total pressure of the air flow on the outer surface of the vehicle body, and the total pressure measuring unit. A traverse means for moving the pressure measuring means along the outer surface of the vehicle body in the longitudinal direction of the vehicle body, and by moving the total pressure measuring means in the longitudinal direction of the vehicle body along the outer surface of the vehicle body by the traverse means. It is characterized in that the air resistance of the vehicle body is measured according to the shape.
従って、本発明によると、車両の車体外表面の空気流の
総圧を測定する総圧測定手段が、トラバース手段によっ
て当該車体の外部形状に応じて、しかも車体前後方向に
自由に移動されるようになっているから、車体外部形状
に応じて変化する実際の空気流に対応して当該各変化位
置の各々の部位で当該空気流の総圧から空気抵抗を容易
かつ正確に測定することができるようになる。Therefore, according to the present invention, the total pressure measuring means for measuring the total pressure of the air flow on the outer surface of the vehicle body of the vehicle can be freely moved by the traverse means according to the external shape of the vehicle body and in the longitudinal direction of the vehicle body. Therefore, it is possible to easily and accurately measure the air resistance from the total pressure of the air flow at each part of each change position corresponding to the actual air flow that changes according to the external shape of the vehicle body. Like
第１図は、本発明の実施例に係る車両の空気抵抗測定装
置の側面図、第２図は、同実施例装置の総圧測定手段お
よびトラバース装置の構成を示す斜視図、第３図は、同
実施例装置の総圧測定手段の詳細な構成を示す一部切欠
側面図、第４図は、上記実施例における空気抵抗測定対
象としての車両の底面図、第５図は、上記実施例におけ
る車体下面形状とそれに応じた総圧係数の変化特性を示
す側面図、第６図(a),(b)は、上記実施例における総圧
測定データのグラフィックディスプレイによる総圧分布
表示パターン図である。 １……車両 １０……総圧測定手段 １１……総圧管 １２……支持部材 １３a……第１のスクリュー軸 １３b……第２のスクリュー軸 １５……第１のパルスモータ １８……第１のタイミングベルト ２０……トラバース手段 ２０Ａ……昇降装置 ２０Ｂ……水平移動装置 ２１a……第３のスクリュー軸 ２１b……第４のスクリュー軸 ２３……第２のパルスモータ ２５……第２のタイミングベルトFIG. 1 is a side view of an air resistance measuring device for a vehicle according to an embodiment of the present invention, FIG. 2 is a perspective view showing a configuration of a total pressure measuring means and a traverse device of the embodiment, and FIG. FIG. 4 is a partially cutaway side view showing the detailed configuration of the total pressure measuring means of the apparatus of the same embodiment, FIG. 4 is a bottom view of a vehicle as an air resistance measurement target in the above embodiment, and FIG. 6A and 6B are side views showing the shape of the lower surface of the vehicle body and the change characteristics of the total pressure coefficient corresponding thereto, and FIGS. 6A and 6B are total pressure distribution display pattern diagrams by the graphic display of the total pressure measurement data in the above embodiment. is there. 1 ... Vehicle 10 ... Total pressure measuring means 11 ... Total pressure tube 12 ... Support member 13a ... First screw shaft 13b ... Second screw shaft 15 ... First pulse motor 18 ... First Timing belt 20 ... Traverse means 20A ... Lifting device 20B ... Horizontal moving device 21a ... Third screw shaft 21b ... Fourth screw shaft 23 ... Second pulse motor 25 ... Second timing belt
Claims (1)
方向に並列配置された複数の圧力センサよりなる総圧測
定手段と、該総圧測定手段を車体外表面に沿って、かつ
車体前後方向に移動するトラバース手段とを備え、上記
総圧測定手段を上記トラバース手段により車体外表面に
沿って車体前後方向に移動させることにより車体外部形
状に対応して車体の空気抵抗を測定するようにした車両
の空気抵抗測定装置。1. A total pressure measuring means comprising a plurality of pressure sensors arranged in parallel in the vehicle width direction for measuring the total pressure of the air flow on the outer surface of the vehicle body, and the total pressure measuring means along the outer surface of the vehicle body. And a traverse means for moving in the longitudinal direction of the vehicle body, wherein the total pressure measuring means is moved in the longitudinal direction of the vehicle body along the outer surface of the vehicle body by the traverse means to measure the air resistance of the vehicle body corresponding to the external shape of the vehicle body. The air resistance measuring device for a vehicle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61164396A JPH0658304B2 (en) | 1986-07-12 | 1986-07-12 | Vehicle air resistance measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61164396A JPH0658304B2 (en) | 1986-07-12 | 1986-07-12 | Vehicle air resistance measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6319530A JPS6319530A (en) | 1988-01-27 |
| JPH0658304B2 true JPH0658304B2 (en) | 1994-08-03 |
Family
ID=15792330
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61164396A Expired - Lifetime JPH0658304B2 (en) | 1986-07-12 | 1986-07-12 | Vehicle air resistance measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0658304B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103376211B (en) * | 2012-04-25 | 2016-02-24 | 广州汽车集团股份有限公司 | The measuring method of coefficient of air resistance during a kind of vehicle sliding |
| JP2015099132A (en) * | 2013-11-20 | 2015-05-28 | トヨタ自動車株式会社 | Chassis dynamo test equipment |
| JP2024157512A (en) * | 2023-04-25 | 2024-11-07 | 三菱重工冷熱株式会社 | Vehicle travel simulation equipment, vehicle travel simulation method, and entrained airflow generation suppression device for the vehicle travel simulation equipment |
-
1986
- 1986-07-12 JP JP61164396A patent/JPH0658304B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6319530A (en) | 1988-01-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5501101A (en) | Demonstration wind tunnel | |
| JP6418972B2 (en) | Wind direction anemometer and wind direction wind speed measurement method | |
| US20170052206A1 (en) | Measurement device and measurement system using same | |
| JPH0658304B2 (en) | Vehicle air resistance measuring device | |
| CA2121200A1 (en) | Automated Flow Measuring Device | |
| CN108195556A (en) | Wind tunnel test auxiliary device and its application method | |
| CN215115095U (en) | Building external wind field simulation test device for wind tunnel test | |
| CN106379564B (en) | Tri-axis micro-interference torque motion simulating device for ground simulation of space vehicles | |
| JPH0658302B2 (en) | Vehicle air flow measurement method | |
| CN208921346U (en) | Turnover plate type wind pressure sensor | |
| JPH06273263A (en) | Wind tunnel | |
| JPH0348166A (en) | Air flow sensor | |
| JPH09101325A (en) | Anemometer calibration device and method | |
| JPH08121381A (en) | Ventilation system for vehicles | |
| JP2002323403A (en) | Golf ball rotating device and golf ball air force measuring device | |
| CN221802894U (en) | A building inclination monitoring device | |
| CN223955615U (en) | A portable water flow velocity measuring device | |
| CN2653514Y (en) | Pipeline wind speed bypass monitoring device | |
| CN223882898U (en) | A positioning device for underground pipeline measurement | |
| CN215984663U (en) | Refrigeration effect detection device for refrigeration equipment | |
| CN103954430B (en) | The FAST VORTEX measuring device of application wind tunnel principle | |
| CN221884504U (en) | Experimental teaching device for measuring gravitational acceleration | |
| CN223362204U (en) | On-site start wind speed calibration device for meteorological use | |
| JP3129372B2 (en) | Airway wall shielding device | |
| CN203837899U (en) | Rapid vorticity measurement device using wind tunnel principle |