declining angle 中文意思是什麼

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 )

對於四面設百葉型風帽，計算表明: l ）正裝傾斜擋板的百葉型風帽可認為是排風型風帽，倒裝擋板傾斜的百葉型風帽可認為是進風型風帽; 2 ）排風型風帽中，擋板正裝30 」 、風帽四個迎風面的有效面積fy和風管凈斷面積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的百葉型風帽排風效果最好; 3 ）進風型風帽中，擋板倒裝裝60 「 、風帽四個迎風面的有效面積和風管凈斷面積的比值（ 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的進風型風帽（ b爪= 2 . 0為最佳）的百葉型風帽進效果最好。

Meanwhile the growing up and declining of east - asian gives us a new angle of view

而東亞的劇起和頓挫，也已經給我們提供了新的歷史高點去反思。

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

對于單側百葉風口的擋雨板，計算表明: 1 ）為了防止雨水隨空氣流入自然進風口，並且使風口盡量少受渦流區的影響，建議選用傾斜角度為45 「的擋雨板; 2 ）建議選用長度比風口高度長100mm - - 200 「的擋雨板，可以較好的避免擋雨板過短將雨水帶入室內和過長影響風口進風的情況。

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

數值模擬採用fluent軟體，計算結果用excel進行處理，通過對大量數值工況進行數值模擬計算，結果表明：對于單側百葉風口，計算表明： 1 ）對于公式p = （ ~ 2 ） 2 ，的理論計算值中定義為流體流經百葉風口內部時的速度，即有效速度，而工程上常使用流體的來流速度來計算，計算表明，的理論計算值與工程應用值的關系為（ _ （理論） ） （ _ （工程） ） = 0 . 813 ； 2 ）當來流速度一定時，擋板傾斜角度越小，壓力損失越小、出口速度越小；因此在要求進口風速比較小的場所，如播音室、圖書館等，宜採用擋板角度30的百葉風口；在要求進口風速比較大的場所，如電影院、辦公室等，百葉擋板的角度應選45 ； 3 ）當來流速度一定時，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，計算表明，鑒于壓力損失、出口風速、板間形成渦流區的大小，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 ）當來流速度一定時，在計算的條件下，當百葉擋板寬度b = 40mm時，百葉擋板的阻力系數最小，考慮到渦流區等的影響，建議選用10mm b 50mm的百葉擋板；西安建築科技大學碩士學位論文5 ）百葉擋板的厚度取為1 . sinln為好; 6 ）百葉擋板的入口側可選用具有傾斜度的楔形擋板來代替矩形擋板，利用其較好的導流作用，可得到更好的出流效果。