scholarly journals ANALYSIS OF PRESSURE LOSS COMPONENTS IN AN INDUSTRIAL EXTRACT DUCT SYSTEM

2016 ◽  
Vol 22 (1) ◽  
Author(s):  
SODIKI JOHN IRISOWENGIBIA
Keyword(s):  
Pressure Loss ◽  
Ventilation System ◽  
Head Loss ◽  
Total Loss ◽  
Duct System ◽  
Branch Duct ◽  
Fan Selection

<p>The frictional head loss and the loss through fittings are computed for branch duct runs of an industrial extract ventilation system. Results show increases of both of the aforementioned loss components with increase in duct length. Furthermore, the fraction of the total loss due to fittings decreases from 0.60 to 0.45, with a corresponding increase of the fraction due to friction (from 0.40 to 0.55).Representative fractions of head loss components, obtained in the manner of this study, are shown to facilitate loss estimates and extract fan selection.</p>

scholarly journals ANALYSIS OF PRESSURE LOSS COMPONENTS IN AN INDUSTRIAL EXTRACT DUCT SYSTEM

2016 ◽  
Vol 22 (1) ◽  
pp. 90-101
Author(s):  
JOHN IRISOWENGIBIA SODIKI
Keyword(s):  
Pressure Loss ◽  
Ventilation System ◽  
Head Loss ◽  
Total Loss ◽  
Duct System ◽  
Branch Duct ◽  
Fan Selection

The frictional head loss and the loss through fittings are computed for branch duct runs of an industrial extract ventilation system. Results show increases of both of the aforementioned loss components with increase in duct length. Furthermore, the fraction of the total loss due to fittings decreases from 0.60 to 0.45, with a corresponding increase of the fraction due to friction (from 0.40 to 0.55).Representative fractions of head loss components, obtained in the manner of this study, are shown to facilitate loss estimates and extract fan selection.

scholarly journals Investigation for additional head loss in helically coiled flexible pipe of a mobile fertigation system

2018 ◽  
Vol 10 ◽  
pp. 01001
Author(s):  
Aliaksandr Basareuski
Keyword(s):  
Pressure Loss ◽  
Energy Intensity ◽  
Specific Energy Consumption ◽  
Head Loss ◽  
Theoretical Studies ◽  
Pipeline Transport ◽  
Flexible Pipe ◽  
System Parameters ◽  
Output Ratio ◽  
Fertilizer System

One of the major parameters of a hydraulic machine is its energy intensity, i.e. its power/output ratio. This article presents the results of theoretical studies of the effects of additional head loss of transporting fluid through helically coiled flexible pipe on specific energy consumption of fertigation machinery and pipeline transport. Computational methods have been used to determine that pressure loss will be 15-20% higher on the average than the loss at a straight section, depending on the average radius of coil helix/design pipe diameter ratio. Correlations have been obtained that allow for justification of major mobile fertilizer system parameters based on the need to minimize pressure loss.

CFD Application on Ventilation System of Hydro-Generator

2011 ◽  
Vol 383-390 ◽  
pp. 3561-3565
Author(s):  
Qun Feng Zhang ◽  
Jin Li Yan ◽  
Min Wang ◽  
Zhi Xiang Chen
Keyword(s):  
Pressure Loss ◽  
Rational Design ◽  
Ventilation System ◽  
Local Pressure ◽  
Porous Media Model ◽  
Air Cooler ◽  
Frame Method ◽  
Flow Flux ◽  
Icem Cfd ◽  
Different Parts

Averaged 3D N-S equations and RNG k-ε equations were solved with parallel computing CFD code on the flow field of dual radial ventilation system without fan for a hydro-generator. The MRF(multiple implicit rotating frame) method was used to simulated the rotating motion of the generator and porous media model were used to simulate the pressure loss of air cooler. Rational tactics were selected to generate calculation grids to compromise with calculation CPU time and result accuracy and the grids of different parts were generated with ICEM-CFD. The flow characteristic of different parts was analyzed and flow flux of different section was obtained. The research indicated that the flow from leakage gap between poles and stators formed "air wall", which generated a recirculation zone and made the bar cooling bad. The local pressure loss of stator entrance is dominant. There are leeward and windward areas for the air flowing with circumferential velocity component. Rational design of stator ducts entrance with some diversion effect, can reduce the pressure loss of the stator ventilation and improve the cooling of leeward area in stator ducts.

scholarly journals Calculation of Hydraulic Resistance in the Case of a Diffuser and a Confuser in a Horizontal Pipe

2021 ◽  
Vol 137 (6) ◽  
pp. 62-64
Author(s):  
A. M. Khurmamatov ◽  
◽  
G. B. Rakhimov ◽  
Keyword(s):  
Hydraulic Resistance ◽  
Pressure Loss ◽  
Head Loss ◽  
Sudden Expansion ◽  
Horizontal Pipe ◽  
Rate Of Increase ◽  
Inner Diameter

The main results of the calculation of the head loss with a smooth expansion and narrowing of the horizontal pipe, which has the following geometric dimensions; - the inner diameter of the pipe with a narrowing of 25 mm and an expansion of 50 mm. The pressure loss of the smooth expansion of the pipe at an oil velocity of 0.2–1.0 m/s has a smooth rate of increase from 0.002 to 0.032 m. With a smooth narrowing of the pipe, the head loss is from 0.0021 to 0.024 m. That, during the movement of oil in a horizontal pipe, the head loss with a sudden expansion is 1.33 times greater than that of a sudden narrowing.

Test and analysis of air flow rate adaptive performance in a distributed fan ventilation system

2021 ◽  
pp. 014362442098600
Author(s):  
Fa-Li Ju ◽  
Qinrong Sun ◽  
Changlei Hou ◽  
Xue Huang ◽  
Xiaoping Yu ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Engineering Design ◽  
Flow Rate ◽  
Air Flow ◽  
Ventilation System ◽  
Adaptive Performance ◽  
Air Flow Rate ◽  
Branch Duct ◽  
Rate Adaptive ◽  
Adaptive Ability

In this study, adaptive branch fan performance in a distributed fan ventilation system was tested. The results demonstrate that the adaptive branch fan stabilises the branch air flow rate within a certain air pressure range corresponding to the branch duct inlet, and this range becomes increasingly narrow as the fan control signal is adjusted to reduce the speed of the fan. The adaptive branch fan is less affected by the main fan and other branch fans in the distributed fan ventilation system because it has a good self-adaptive ability of ventilation duct resistance characteristics and anti-interference ability of the air flow rate. Furthermore, the hydraulic characteristics of the branch fans in the distributed fan ventilation system were analysed. The new performance characterisation parameters and method for modifying the engineering design for the adaptive branch fan were presented. Practical application: This study investigates the adaptive performance of the branch fan in a distributed fan ventilation system. Our results demonstrate that the new branch fan can stabilise the air flow rate in a mechanical ventilation system. More importantly, we not only propose performance characterisation parameters of the adaptive branch fan that are important for understanding the operation of a mechanical ventilation system, but also present a method of engineering design application. This study can guide the design and operation of mechanical ventilation systems.

scholarly journals Pressure loss reduction of pipe elements

2020 ◽  
Vol 15 (2) ◽  
pp. 489-493
Author(s):  
Gábor Gönczi
Keyword(s):  
Pressure Loss ◽  
Head Loss ◽  
Theoretical Research ◽  
Loss Reduction ◽  
Target Value ◽  
Discharge Pipe ◽  
Pipe Networks ◽  
Physical Experiments ◽  
Pump Station ◽  
Pump Stations

Abstract A theoretical research was conducted from 2016 to 2018 which aimed to reduce the head loss of pipe networks in the pump stations. The results were promising and predicted an average head loss reduction by 30%. Afterwards, physical experiments were carried out to test the effectiveness of the new pipe designs. Two new prototype pipe sections were installed into one of our pump stations. The experiment was successful as two unique pipe sections installed in the discharge pipe reduced the head loss of the pump station by 25–26%. According to these results, we can set a target value of 30% head loss reduction at full pump station pipe reconstruction.

scholarly journals Rancang Bangun Trainer Friction Loss Pada Sistem Perpipaan Sebagai Media Pembelajaran Di Laboratorium Mekanika Fluida Pada Jurusan Teknik Mesin Unesa

Otopro ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Diastian Vinaya Wijanarko ◽  
I Made Arsana ◽  
Bellina Yunitasari
Keyword(s):  
Pressure Loss ◽  
Pressure Gauge ◽  
Head Loss ◽  
Friction Loss ◽  
Flow Meter

Rancang bangun trainer friction loss pada sistem perpipaan telah selesai di uji pada penelitian ini.  Bahan pipa terbuat dari westpex, tekanan air diukur dengan menggunakan pressure gauge, pengukur debit menggunakan flow meter. Pengkuran akan dilakukan pada bukaan katub seperempat, setengah, tigaperempat, dan penuh. Hasil pengujian alat akan diolah kedalam bentuk head loss, pressure loss, kecepatan aliran, bilangan Reynolds, dan koefisien gesek pipa. Berdasarkan hasil yang telah dicapai, kesimpulan yang didapatkan adalah head loss meberikan hasil semakin meningkat pada bukaan katub setengah sampai penuh, pressure loss memberikan hasil yang semakin meningkat pada bukaan katub seperempat sampai penuh, kecepatan aliran aliran pada bukaan katub seperempat sampai penuh semakin besar sehingga bilangan Reynolds meningkat mengikuti besarnya bilangan Reynold, dan koefisien gesek pipa pada setiap bukaan katub seperempat sampai penuh menurun.

Laminar Pressure Loss Coefficient in Close Coupled Fittings

2006 ◽  
Author(s):  
Murthy Lakshmiraju ◽  
Jie Cui
Keyword(s):  
Reynolds Number ◽  
Pressure Loss ◽  
Total Pressure ◽  
Laminar Flows ◽  
Loss Coefficient ◽  
Piping System ◽  
Duct System ◽  
Pressure Loss Coefficient ◽  
Intermediate Distance ◽  
Loss Coefficients

Close-coupled fittings are widely used in piping system to change the direction of the fluid and to connect pipes. These fittings cause losses and these losses play a significant role in the total pressure loss in a duct system. Numerical simulations were performed using Fluent on laminar flows in a circular pipe to obtain pressure loss coefficients associated with different fittings of two elbows and three elbows. Each configuration was studied with different intermediate distances between fittings of 0, 1, 3, 5, and 10 pipe diameters. It was observed that for a Reynolds number of 100 and for an intermediate distance less than 5 pipe diameters, the pressure loss coefficient for the coupled fittings was less than that of the uncoupled fittings. While the fittings become uncoupled when the intermediate distance was greater than 5 pipe diameters. Variation of velocity along the axis of the pipe was analyzed to understand the mechanism of the pressure loss for various fitting configurations with different intermediate distances.

scholarly journals The Mechanical Impact of Aerodynamic Stall on Tunnel Ventilation Fans

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
A. G. Sheard ◽  
A. Corsini
Keyword(s):  
Mechanical Design ◽  
Ventilation System ◽  
Peak Stress ◽  
Aerodynamic Characteristics ◽  
Selection Strategy ◽  
Blade Angle ◽  
Tunnel Ventilation ◽  
Advantages And Disadvantages ◽  
Fan Selection ◽  
Ventilation Fan

This paper describes work aimed at establishing the ability of a tunnel ventilation fan to operate without risk of mechanical failure in the event of aerodynamic stall. The research establishes the aerodynamic characteristics of a typical tunnel ventilation fan when operated in both stable and stalled aerodynamic conditions, with and without an anti-stall stabilisation ring, with and without a “nonstalling” blade angle and at full, half, and one quarter design speed. It also measures the fan’s peak stress, thus facilitating an analysis of the implications of the experimental results for mechanical design methodology. The paper concludes by presenting three different strategies for tunnel ventilation fan selection in applications where the selected fan will most likely stall. The first strategy selects a fan with a low-blade angle that is nonstalling. The second strategy selects a fan with a high-pressure developing capability. The third strategy selects a fan with a fitted stabilisation ring. Tunnel ventilation system designers each have their favoured fan selection strategy. However, all three strategies can produce system designs within which a tunnel ventilation fan performs reliably in-service. The paper considers the advantages and disadvantages of each selection strategy and considered the strengths and weaknesses of each.

scholarly journals Experimental and Numerical analysis of Flow characteristics of sand water slurry in a horizontal pipe

2021 ◽  
Author(s):  
Varinder Singh ◽  
◽  
Satish Kumar ◽  
Dwarikanath Ratha ◽  
◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Pressure Loss ◽  
Volume Fraction ◽  
Head Loss ◽  
Experimental Results ◽  
Solid Concentration ◽  
Horizontal Pipe ◽  
Slurry Concentration ◽  
Water Slurry ◽  
Test Loop

The transportation of the solid material using hydraulic transportation method is economically the best method. The head loss occurs during transportation of slurry through horizontal pipelines usually depends on the rheological behavior of slurry, slurry concentration, particle size, and influx velocity. An experimental investigation has been performed using sand-water slurry flowing through the horizontal pipe section of a pilot plant test loop. The head loss obtained from the experimental results was validated through CFD simulation using FLUENT. The solid concentration of sand-water slurry and influx velocity used during both experiments and numerical simulation were in the range of 10-40% (by weight) and 1 to 4 m/s respectively. The numerical simulations were performed using five different turbulence models and the results obtained using SST k-omega model was in close agreement with experimental results. It is observed from both the experiment and numerical analysis that the pressure loss, granular pressure, volume fraction and skin fraction coefficient during transportation of slurry through a horizontal pipe is a function of solid concentration and influx velocity. The present study observed that as the flow velocity increases four times, the pressure loss is increasing more than 10 times. Uniform volume fraction at middle zone of outlet of the pipe is observed as both the slurry concentration and velocity of flow increases.

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