- 衰減角
- decline: vi. 1.下傾，下降；跌落；歪斜；(樹(shù)枝等)下垂，(頭 ...
- angle: n. 〔古語(yǔ)〕釣鉤；釣具。 a brother of t ...
- curve of declining angle: 橫搖衰減曲線; 曲線
- declining: 傾斜的, 衰退中的; 下滑的,衰退的
- a declining birthrate: 在下降中的出生率
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declining angle中文什么意思
- 衰減角
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例句與用法
- For hoods with shutters in four sides , the results show : 1 ) the hoods positively placed boards are called hoods used for venting airflow ; hoods negatively placed boards are called hoods used for leading airflow ; 2 ) among the hoods used for venting airflow , the most effective hoods should have positive declining angle value of 30 , the ratio 4 of areas between the four windward faces and the gular section ( fy / fj = 4 ) , the value of b range from 70 mm to 120 mm and the value of b / h range from 0 . 5 to 0 . 6 ; 3 ) the most effective hoods should have negative declining angle value of 60 , the ratio 4 of areas between the four windward faces and the gular section ( fy / fj = 4 ) , the value of b range from 100 mm to 170 mm ( the optimum value is 120 mm ) and the value of b / h range from 1 . 4 to 2 . 2 ( the optimum value is 2 . 0 )
對(duì)于四面設(shè)百葉型風(fēng)帽，計(jì)算表明: l )正裝傾斜擋板的百葉型風(fēng)帽可認(rèn)為是排風(fēng)型風(fēng)帽，倒裝擋板傾斜的百葉型風(fēng)帽可認(rèn)為是進(jìn)風(fēng)型風(fēng)帽; 2 )排風(fēng)型風(fēng)帽中，擋板正裝30 ” 、風(fēng)帽四個(gè)迎風(fēng)面的有效面積fy和風(fēng)管凈斷面積fj的比值( fy腸)為4 、擋板寬度b在70inln到120inln之間、板間距比值隴在0 . 5到0 . 6的百葉型風(fēng)帽排風(fēng)效果最好; 3 )進(jìn)風(fēng)型風(fēng)帽中，擋板倒裝裝60 “ 、風(fēng)帽四個(gè)迎風(fēng)面的有效面積和風(fēng)管凈斷面積的比值( fy例)為4 、擋板寬度b在100咖到170mm之間( 120mm為最佳) 、板間距比值隴在1 . 4到2 . 0的進(jìn)風(fēng)型風(fēng)帽( b爪= 2 . 0為最佳)的百葉型風(fēng)帽進(jìn)效果最好。 - For shelters , the results show : 1 ) to reduce the raining drops entering into the inlet and to decrease the influence of the vortex , the declining angle of 45 is recommended for the shelters ; 2 ) it is better to choose those shelters which are longer 100 mm ~ 200 mm than the height of the inlets , as they may protect the room from rain
對(duì)于單側(cè)百葉風(fēng)口的擋雨板，計(jì)算表明: 1 )為了防止雨水隨空氣流入自然進(jìn)風(fēng)口，并且使風(fēng)口盡量少受渦流區(qū)的影響，建議選用傾斜角度為45 “的擋雨板; 2 )建議選用長(zhǎng)度比風(fēng)口高度長(zhǎng)100mm - - 200 “的擋雨板，可以較好的避免擋雨板過(guò)短將雨水帶入室內(nèi)和過(guò)長(zhǎng)影響風(fēng)口進(jìn)風(fēng)的情況。 - For shutters , the results show : 1 ) according to the formula p = , the theoretical value of is calculated by the effective velocity of the flow , and its engineering value is calculated by the arriving velocity of the flow , the relationship between the theoretical value of and its engineering value is 2 ) the smaller value of declining angle will result in the smaller pressure loss and smaller outlet velocities . as a result , the declining angle of 30 擄 or less is recommended in some places which need small wind velocity , such as broadcasting studio and library , and the declining angle of 45 擄 or less is recommended in places which need big wind velocity , such as cinema and office ; 3 ) the larger value of ratio between the wide of the shutter b and the space between two boards h ( b / h ) will result in the larger pressure loss and smaller outlet velocities . the range of b / h from 0 . 8 to 2 . 0 and the optimum value 1 . 2 is recommended ; 4 ) the range of b from 10 mm to 50 nun and the optimum value 40 mm is recommended ; 5 ) the proper thickness of the boards 8 of the shutters is 1 . 5 mm ; 6 ) cuneiform boards should replace the rectangle inlet boards of the shutters in order to obtain better ventilation
數(shù)值模擬采用fluent軟件，計(jì)算結(jié)果用excel進(jìn)行處理，通過(guò)對(duì)大量數(shù)值工況進(jìn)行數(shù)值模擬計(jì)算，結(jié)果表明：對(duì)于單側(cè)百葉風(fēng)口，計(jì)算表明： 1 )對(duì)于公式p = ( ~ 2 ) 2 ，的理論計(jì)算值中定義為流體流經(jīng)百葉風(fēng)口內(nèi)部時(shí)的速度，即有效速度，而工程上常使用流體的來(lái)流速度來(lái)計(jì)算，計(jì)算表明，的理論計(jì)算值與工程應(yīng)用值的關(guān)系為( _ (理論) ) ( _ (工程) ) = 0 . 813 ； 2 )當(dāng)來(lái)流速度一定時(shí)，擋板傾斜角度越小，壓力損失越小、出口速度越??；因此在要求進(jìn)口風(fēng)速比較小的場(chǎng)所，如播音室、圖書館等，宜采用擋板角度30的百葉風(fēng)口；在要求進(jìn)口風(fēng)速比較大的場(chǎng)所，如電影院、辦公室等，百葉擋板的角度應(yīng)選45 ； 3 )當(dāng)來(lái)流速度一定時(shí)，百葉擋板的擋板寬度b與擋板間距h的比值b h越大，壓力損失越大，出口速度越小，計(jì)算表明，鑒于壓力損失、出口風(fēng)速、板間形成渦流區(qū)的大小，百葉擋板的b h值取0 . 8到2 . 0之間， b h = 1 . 2為最佳值； 4 )當(dāng)來(lái)流速度一定時(shí)，在計(jì)算的條件下，當(dāng)百葉擋板寬度b = 40mm時(shí)，百葉擋板的阻力系數(shù)最小，考慮到渦流區(qū)等的影響，建議選用10mm b 50mm的百葉擋板；西安建筑科技大學(xué)碩士學(xué)位論文5 )百葉擋板的厚度取為1 . sinln為好; 6 )百葉擋板的入口側(cè)可選用具有傾斜度的楔形擋板來(lái)代替矩形擋板，利用其較好的導(dǎo)流作用，可得到更好的出流效果。