TeTau Reynolds (Re)ko tētahi o ngā tawhā kore-ahu tino nui i roto i te miihini wai. He āwhina ki te whakaahua i te whanaungatanga i waenga ingā kaha ātete me ngā kaha matotorui roto i tētahi wai e rere ana, ā, e whakamahia whānuitia ana hei whakatau mēnā heāhua papatahi, āhua whakawhiti, āhua pōrearea rānei.

Mō te ine i te rere o te ultrasonic, he mea nui te tau Reynolds nā te mea ka pā tika te pūnaha rere ki tete tere o te nekehanga i roto i te paipa. I te mea ka ine te mita rere ultrasonic i te tere o te wai i te ara oro, ā, ka whakamahia aua mōhiohio hei whakatau i te tere rere toharite, ka pāngia te tika o te ine e ngā huringa o te kōtaha tere.

1. He aha te Tau Reynolds?

Mō te rere o te wai i roto i te paipa, ka taea te whakaatu i te tau Reynolds penei:

Re = ρVD / μ

rānei:

Re = VD / ν

kei hea:

• Re= Tau Reynolds
• ρ= te mātotoru wai
• V= te tere rere toharite
• D= te whānui o roto o te paipa
• μ= matotoru hihiri
• ν= matotoru kinematic

Kāore he whānuitanga o te Tau Reynolds.

I te nuinga o te wā, mō te rere i roto i te paipa porowhita:

• Re < tata ki te 2,300→ Rere rere
• Re ≈ 2,300–4,000→ Rere whakawhiti
• Re > tata ki te 4,000→ Rere pōrearea

He aratohu whānui ēnei uara, ehara i te rohe tuturu, nā te mea ka rerekē pea ngā āhuatanga rere tuturu i runga i te āhua o te paipa me ngā raruraru.

2. He aha te rerekētanga i waenganui i te rere Laminar me te rere Turbulent?

Ko te rerekētanga matua ko te huarahi e tohatohahia ai te tere puta noa i te paipa.

Rere Whakamārama

I te rere laminar, ka neke te wai i roto i ngā paparanga tino tika.

Ko te tere o te nekehanga he mea tino kitea ake, arā:

• Te tere iti iho i te taha o te pakitara o te paipa
• Te tere teitei ake ki te pokapū
• He kōtaha tere parabolic e matapaetia ana

Ko tētahi whakaaturanga māmā ko:

Pakitara → Tere Iti → Tere Nui → Tere Iti → Pakitara

Rere Pōrearea

I roto i te rere pōrearea, he tino koretake ake te nekehanga o te wai.

Mā ngā piki me ngā heke iti o te tauine me te whakaranu ka papatahi te āhua o te tere ki te whakaritea ki te rere laminar.

Ko te tikanga o tēnei ka tino rerekē te tohatoha tere puta noa i te paipa me te tau Reynolds.

3. He aha te hiranga o tēnei ki te mita rere oro-ā-oro?

Kāore te mita rere ultrasonic e ine tika i te rōrahi katoa o te wai e rere ana i roto i te paipa.

Engari, ka ine i tete tere o te waikātahi ka tatau i te tere rere rōrahi.

I roto i te āhua māmā:

Q = V × A

kei hea:

• Q= te tere rere rōrahi
• V= te tere rere toharite
• A= horahanga whakawhiti-wāhanga paipa

Ko te wero, ko te tere i inehia i te ara oro ultrasonic kāore pea e tino ōrite ki te tere toharite puta noa i te paipa katoa.

Nō reira, me whai whakaaro te taputapu ki te whanaungatanga i waenga i te tere oro i inehia me te tere rere toharite tuturu.

He kaha te awe o te tere ki tēnei whanaungatanga.

4. Me pēhea te hurihanga o te Tau Reynolds i te kōtaha tere?

Whakaarohia ngā āhuatanga e rua.

Tau Reynolds Iti

I te Re iti, ka rere pea te rere i roto i te āhua laminar.

He tino piko te kōtaha tere:

Tere waenga > Tere toharite > Tere tata-pakitara

Mena ka haere te ara oro ultrasonic mā roto i tētahi wāhanga motuhake o te paipa, ka rerekē pea te tere ine mai i te tere toharite whakawhiti-wāhanga.

Tau Reynolds Teitei

I te Re teitei ake, ka pōrearea te rere.

Ahakoa ka heke tonu te tere ki te pakitara o te paipa, ka puta he āhua papatahi o te tere i te whakaranu.

Nō reira, he rerekē te whanaungatanga o te tere ara-oro ki te tere paipa toharite.

Koinei tētahi take e kore ai e taea e te mita rere ultrasonic te kī noa he rite tonu te tere kotahi i ine ki te tere rere toharite.

5. Ngā Mita Rere Ultrasonic Nama Reynolds me te Wā-Waka

Mō te mita rere ultrasonic wā-haere, ka ine te taputapu i te rerekētanga i waenga i ngā wā whakawhiti ultrasonic o runga me o raro.

Ka taea te whakangawari i te whanaungatanga taketake penei:

Te Tere Rere ∝ Te Rerekētanga o te Wā-Waka

E pā ana te tere i ine ki te wāhanga tere i te ara oro ultrasonic.

Heoi, ko te tere rere o te rōrahi tuturu e whakawhirinaki ana kite tere toharite puta noa i te wāhanga whakawhiti paipa katoa.

Nō reira, me hono e te taputapu te tere oro i inehia ki te tere rere toharite.

Ka pāngia pea tēnei whanaungatanga e:

• Tau Reynolds
• Tauwāhi ara oro
• Te maha o ngā ara oro
• Kōtaha rere
• Diameter o te paipa
• Ngā raruraru rere

6. He aha te hiranga ake o te pānga i ngā tere rere iti?

Mai i:

Re = ρVD / μ

Ina heke te tere o te rere, ka heke anō hoki te tau Reynolds.

Hei tauira, ko tētahi pūnaha e whakahaere ana i tētahi tere rere teitei, tērā pea kua tino whanake te rere pōrearea, engari ko taua pūnaha anō e whakahaere ana i tētahi tere rere tino iti, tērā pea ka tata ki te pūnaha whakawhiti, ki te pūnaha papatahi rānei.

Nō reira, ka taea te whakarerekē nui i te tere o te rere o te wai i te mea ka rerekē te tere o te rere.

Ko te tikanga tēnei ko te whanaungatanga i waenganui i:

Te tere o te ara oro

me

Te tere paipa toharite

tērā pea ka huri anō hoki.

Mō ētahi mita rere ultrasonic, he mea nui tēnei hei whakaaroaro ina ine ana i ngā tere rere tino iti, i ngā wai tino matotoru rānei.

7. He aha te hiranga o te matotoru o te wai?

He pānga whakahuri te tau Reynolds ki te matotoru:

Re = ρVD / μ

Ki te piki ake te matotoru, ka heke te Tau Reynolds mō te diameter o te paipa, te mātotoru, me te tere rere.

Hei tauira, whakaarohia kia rua ngā wai e rere ana i te tere ōrite i roto i te paipa kotahi:

Wai → Matotoru iti → Re teitei ake

Hinu taumaha → Te matotoru teitei → Te Re iti iho

Tērā pea he nui ake te tere o te hinu taumaha nā te mea he nui ake tōna matotoru.

Nō reira, ka rerekē pea te whanonga o te mita rere ultrasonic kotahi ina ine ana i ngā wai rerekē, ahakoa he rite te whānui o te paipa me te tere rere.

8. He aha te hononga o te roa o te paipa tika ki te tau Reynolds?

Ka āwhina anō te Tau Reynolds ki te whakamārama he aha te hiranga o te roa tika o te paipa.

I muri i te hononga o te tuke, te takirere, te whakaiti, tetahi atu taputapu rānei, ka raru pea te rere o te wai.

Me rawaka te tawhiti e hiahiatia ana mō te rere kia whanake ai ki tētahi kōtaha pumau ake.

Ko te tukanga whanaketanga e whakawhirinaki ana ki ngā āhuatanga tae atu ki:

• Tau Reynolds
• Diameter o te paipa
• Te taratara o te paipa
• Momo whakararuraru
• Te tere o te rere

Mena ka tāutahia te mita rere ultrasonic ki te tata rawa atu o te raruraru o te awa, ka pāngia pea te tere oro i inehia e te tere kore taurite, te tere hurihuri rānei.

Ka taea e tēnei te whakaputa hapa ine.

Koia te take e taunaki ana te aratohu tāutanga noa mō te mita rere ultrasonic:

Paipa tika o runga ≥ 10D

Paipa tika iho i raro i te awa ≥ 5D

kei heaKo D te diameter o roto o te paipa.

9. He Tikanga Pai Ake te Tau Reynolds Nui Ake?

Kāore i te tino hiahiatia.

Ko te tau Reynolds teitei ake he tohu i te rere pōrearea ake, engari ko te tika o te ine e whakawhirinaki ana ki ngā āhuatanga maha atu.

Kei roto i ēnei:

• Kōtaha rere
• Tāutanga o te whakawhiti hiko
• Āhua o te paipa
• Te roa o te paipa tika
• Kounga tohu
• Whirihoranga ara oro
• Ngā āhuatanga wai
• Te whakatikatika i te mita

Nō reira, me whakaaro ko te tau Reynolds he mea nuitawhā āhua-rere, kaua hei tohu tika mō te tika o te mita rere.

10. He aha i iti ake ai te aro o ngā mita rere ultrasonic maha-ara ki te kōtaha rere?

Koinei tētahi o ngā painga nui o te ine rere ultrasonic maha-ara.

Ka tangohia te tere e te ara oro kotahi i tētahi rohe iti o te paipa.

Ka whakamahia e te mita rere maha-ara ētahi ara oro maha i ngā tūranga rerekē.

Ā-kaupapa:

Ara Kotahi

→ Ine i te tere i te ara oro kotahi

Ara-maha

→ Ka tauira i ngā rohe maha o te paipa

Ka taea e te taputapu te whakamahi i ēnei inenga hei whakatau i te tohatoha tere whānui.

Nō reira, he pai ake ngā mita rere ultrasonic maha-ara mō ngā tono ina:

• He uaua te āhua o te rere
• E hiahiatia ana te tino tika
• He nui te diameter o te paipa
• He uaua ki te karo i ngā raruraru rere

Ka pā te tau Reynolds ki te ine rere o te ultrasonic nā te mea ka pā ki tete āhua rere me te tere o roto i te paipa.

Ko te whanaungatanga taketake ko:

Re = ρVD / μ

I te hurihanga o te tau Reynolds, ka taea te whakawhiti i te rere i waenga i ngā tikanga laminar, transitional, me turbulent. Ka huri tēnei i te tohatoha tere puta noa i te paipa, ā, ka pā ki te whanaungatanga i waenga i te tere i inehia i te ara oro ultrasonic me te tere rere toharite tuturu.

Mō te ine i te rere o te ultrasonic, me whai whakaaro tahi te tau Reynolds me:

Tere rere + Matotoru wai + Diameter paipa + Kōtaha rere + Roa paipa tika + Whirihoranga ara oro

Mā te mārama ki te tau Reynolds ka āwhina i ngā kaihangarau ki te aromatawai pai akengā āhuatanga rere, te tāutanga o te pūoko, te koretake o te ine, me te pai o te mita rere ultrasonic mō tētahi tono motuhake.