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Calculation of Local Drag Coefficients (LDC)
Tees
Merging Tee, type Fб+Fп>Fс;Fп=Fс; α=90°.
[Idelchik's Handbook, diag.#7-4] Re>4000
![Вытяжной типа FБ + FП > FC; FП = FC; α=90°](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/7-4.jpg)
Merging Tee, symmetrical with sharp junction on 90°.
[Idelchik's Handbook, diag.#7-29]
![Вытяжной (на слияние) симметричной формы (равносторонний) с резким поворотом на 90°](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/7-29_conv.jpg)
Merging Tee, symmetrical equilateral with junction on 90° - sharp and shaped.
[Results of numerical and experimental research. Ziganshin A.M., Safiullina G.R.]
nonshaped - standard |
shaped - energy efficient |
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Diverging Tee, type Fб+Fп>Fс;Fп=Fс; hб=hс; α=90°.
[Idelchik's Handbook, diag.#7-20.1] до wб/wс=2,0
(аппроксимация табличных данных, ошибка не более 15%)
![Приточный типа F<sub>б</sub>+F<sub>п</sub>>F<sub>с</sub>;F<sub>п</sub>=F<sub>с</sub>; h<sub>б</sub>=h<sub>с</sub>; α=90°.](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/7-20_1.jpg)
Diverging Tee, symmetrical equilateral with sharp juntion on 90°.
[Idelchik's Handbook, diag.#7-29] для сварных тройников k=0.3; для чугунных стандартных тройников на резьбе k=1.5
![Приточный (на разделение) симметричной формы (равносторонний) с резким поворотом на 90°.](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/7-29_div.jpg)
Merging Tee, type Fб=Fп=Fс; α=90°; shaped
[Results of numerical and experimental research. Ziganshin A.M., Badykova L.N.] Re>10000
![Вытяжной типа Fб=Fп=Fс; α=90°; профилированный](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/7-4prof.jpg)
Elbows
Sharp elbows; α=90°.
[Idelchik's Handbook, diag.#6-6] для Re>3·103 и абс. шероховатостью Δ, мм
(аппроксимация табличных данных в диапазоне 0.25 < a0/b0 < 10; 0.6 < b1/b0 < 2, ошибка не более 15%)
ζ= ζ´•kΔ•kReAbsolute roughness of some materials, mm
Steel pipes: 0.02-0.1 | Reinforced concrete: 2.5 |
Cast iron pipes: 0.25-1.00 | Brick: 4 |
Sheet steel:0.1-0.15 | Cement mortar plaster channel:0.05-0.22 |
![Колена с острыми кромками; α=90°](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/6-6.jpg)
Shaped elbow; α=90°; профилированные.
[Results of numerical and experimental research. Ziganshin A.M., Belyaeva E.E.] Re>1·105 и абс. шероховатостью Δ, мм
(аппроксимация численных данных в диапазоне 0.25 < a0/b0 < 10; 0.6 < b1/b0 < 3, ошибка не более 20%)
ζ= ζ´•kΔ•kReAbsolute roughness of some materials, mm
Steel pipes: 0.02-0.1 | Reinforced concrete: 2.5 |
Cast iron pipes: 0.25-1.00 | Brick: 4 |
Sheet steel:0.1-0.15 | Cement mortar plaster channel:0.05-0.22 |
![Колена с острыми кромками; α=90°](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/ElbProf.jpg)
ПU-shaped elbow α=90°; shaped
[Results of numerical research. Ziganshin A.M., Ozerov A.O., Solodova E.E.]
application area 0.5< l / b <15 (not shaped) и 0.5< l / b <7 (shaped) ; shaping is performed for rectangular ducts, according to specially defined outlines.
![П-образные колена с острыми кромками; ?=90°](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/PElb.jpg)
Supply Exits
Mid-point lateral exit
[Experimental data of Taliev V.N. и numerical studies of A.M. Ziganshin, G.A. Gimadieva]
(data approximation in the range 0.225 <f < 2.4; 0 < q < 1,error not more 12%)
![Приточное среднее боковое отверстие](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/MidOrif.jpg)
Lateral exit at the end of the duct
[Experimental data of Khanzhonkov V.I. и numerical studies of A.M. Ziganshin, K.E.Batrova]
(data approximation in the range 0.2 <f < 2, erroe no more than 8%)
![Приточное последнее боковое отверстие](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/EndOrif.jpg)
Exhaust entries
Lateral entry at the end of the duct (2D case)
Non shaped design [numerical studies of A.M. Ziganshin, K.E.Batrova]
(data approximation in the range 0.2 < h/b < 1.9, error no more than 5%)
Shaped design [numerical studies of A.M. Ziganshin, K.E.Batrova](data approximation in the range 0.2 < h/b < 1.9, error no more than 5%)
![Раструб (конический коллектор)](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/ExOrLst.jpg)
Mid-point lateral entry (2D case)
Nonshaped design [Numerical studies of A.M. Ziganshin, K.E.Batrova, G.A. Gimadieva]
(data approximation in the range 0.1 < GO/GC < 0.95, и 0.32 < h/B < 2
![Среднее боковое отверстие](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/ExOrMid_.jpg)
Round exhaust hood;
Nonshaped design [Idelchik's Handbook diag.#3-6]
(data approximation in the range 5° <α <80°; 0.05 < d/R < 2 (для α=5°) ÷ 11 (для α=80°), error no more than 20%)
Shaped design [Numerical studies of A.M. Ziganshin](data is correct in range 30° <α <90°; 1 < d/R < 4,5, error no more than 19%)
![Раструб (конический коллектор)](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/rastr.jpg)
Slot exhaust hood
Nonshaped design [Numerical studies of A.M. Ziganshin]
(LDC for discrete angles from 0° to 90°; 0.5 < d/B < 2.5, error no more than 10%)
Shaped design [Numerical studies of A.M. Ziganshin](LDC for discrete angles from 0° to 90°; 0.5 < d/B < 2.5, error no more than10%)
![Раструб плоский](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/rastrPl.jpg)
Transitions
Sudden Expansion
non shaped by [Idelchik's Handbook, diag. 4-1] Re>3.3·103
shaped-numerical studies Ziganshin A.M., Naumov T.A.
application area 0.1< F0 / F2<0.7;shaping is performed for rectangular ducts, according to specially defined outlines.
![Внезапное расширение](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/4-1_prof.jpg)
Sudden Constriction
[Idelchik's Handbook, diag.#4-9.1] Re>1·104
![Внезапное сужение](/universitet/structure/instituty/isties/ktgv/obrazovanie/bakalavriat-umm/vent/Calculator_files/4-9_1.jpg)
References
1. Идельчик И. Е. Справочник по гидравлическим сопротивлениям/ Под ред. М. О. Штейнберга. – 3-е изд., перераб. и доп. М.: Машиностроение, 1992. 672 с.
4. Талиев В.Н. Аэродинамика вентиляции. М. : Стройиздат, 1954. 288 с.
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