Koj paub ntau npaum li cas txog thermal anemometers
Ib lub ntsuas ntsuas ceev uas hloov cov teeb liab ntws mus rau hauv lub teeb liab hluav taws xob, thiab tuaj yeem ntsuas cov dej kub lossis qhov ntom ntom. Lub hauv paus ntsiab lus yog hais tias ib tug nyias hlau hlau rhuab los ntawm hluav taws xob (hu ua kub hlau) yog muab tso rau hauv lub airflow, lub tshav kub dissipation ntawm kub hlau nyob rau hauv lub airflow muaj feem xyuam rau cov khiav ceev, thiab lub tshav kub dissipation ua rau kub hloov ntawm lub cov hlau kub kub ua rau muaj kev hloov pauv hauv qhov tsis kam, thiab cov teeb liab ntws tawm tau hloov mus rau hauv hluav taws xob teeb liab. Nws muaj ob hom kev ua haujlwm: ① ntws tsis tu ncua. Tam sim no los ntawm cov hlau kub tseem nyob tas li. Thaum qhov kub thiab txias hloov, qhov tsis kam ntawm cov hlau kub hloov, yog li qhov hluav taws xob hla ntawm ob qhov kawg hloov, yog li ntsuas qhov ntws. ② Hom kub tsis tu ncua. Qhov kub ntawm cov hlau kub yog khaws cia tsis tu ncua, xws li 150 degree, thiab tus nqi ntws tuaj yeem ntsuas raws li qhov xav tau tam sim no. Cov hom kub tsis tu ncua yog siv dav dua li hom ntws tsis tu ncua.
Qhov ntev ntawm cov hlau kub yog feem ntau nyob rau hauv qhov ntau ntawm {{0}} 5-2 hli, txoj kab uas hla yog nyob rau hauv thaj tsam ntawm 1-10 microns, thiab cov khoom yog platinum, tungsten los yog platinum-rhodium alloy. Yog tias nyias nyias (thickness tsawg dua 0.1 micron) cov yeeb yaj kiab hlau siv los hloov cov hlau hlau, nws yog cov yeeb yaj kiab kub anemometer, uas muaj cov haujlwm zoo sib xws rau cov hlau kub, tab sis feem ntau yog siv rau ntsuas qhov ntws ntawm cov kua. Ntxiv rau qhov zoo tib yam ib leeg-xaim, cov hlau kub kuj tseem tuaj yeem ua ke ob-xaim lossis peb-xaim hom los ntsuas qhov nrawm ntawm txhua qhov kev qhia. Cov hluav taws xob teeb liab tso tawm los ntawm tus xov tooj hotline yog nkag mus rau hauv lub computer tom qab amplification, them nyiaj thiab digitization, uas tuaj yeem txhim kho qhov ntsuas qhov tseeb, tuaj yeem ua tiav cov ntaub ntawv tom qab ua tiav cov txheej txheem, thiab nthuav cov kev ntsuas ceev, xws li ua tiav cov nqi tam sim thiab lub sij hawm nruab nrab tus nqi, ua ke ceev thiab ib nrab ceev, thiab turbulence. thiab lwm yam kev ntsuas ntawm turbulence parameters. Piv nrog rau lub pitot raj, lub kub hlau anemometer [1] muaj qhov zoo ntawm me me sojntsuam ntim, kev cuam tshuam me me rau qhov chaw ntws, cov lus teb ceev ceev, thiab tuaj yeem ntsuas qhov tsis txaus siab tshaj tawm; Nws tuaj yeem ntsuas qhov nrawm nrawm (xws li qis li 0.3 m / s).
Thaum siv thermal probes nyob rau hauv turbulent flow, airflow los ntawm tag nrho cov lus qhia impinges rau lub thermal caij ib txhij, uas yuav cuam tshuam qhov tseeb ntawm qhov ntsuas. Thaum ntsuas nyob rau hauv turbulent flow, qhov taw qhia tus nqi ntawm lub thermal anemometer flow sensor yog feem ntau siab dua li ntawm lub teb sojntsuam. Cov tshwm sim saum toj no tuaj yeem pom nyob rau hauv cov txheej txheem ntsuas cov kav dej. Nyob ntawm tus qauv tsim ntawm kev tswj cov yeeb nkab turbulence, nws tuaj yeem tshwm sim txawm tias qis qis. Yog li ntawd, cov txheej txheem ntsuas anemometer yuav tsum tau nqa tawm ntawm qhov ncaj ntawm cov kav dej. Qhov pib ntawm txoj kab ncaj nraim yuav tsum yog tsawg kawg yog 10 × D (D= txoj kab uas hla hauv CM) ua ntej qhov ntsuas ntsuas; qhov kawg taw tes yuav tsum yog tsawg kawg yog 4 × D tom qab ntsuas ntsuas. Cov kua dej yuav tsum tsis txhob muaj occlusions (ntug, overhangs, khoom, thiab lwm yam).
