scholarly journals Analisa Kerugian Head Akibat Perluasan Dan Penyempitan Penampang Pada Sambungan 90o

2021 ◽  
Vol 1 (1) ◽  
pp. 46-55
Author(s):  
Ahmad Yani ◽  
Ratnawati ◽  
Ardyanto Darmanto
Keyword(s):  
Stainless Steel ◽  
Cross Section ◽  
Flow Rate ◽  
Pipe Flow ◽  
Head Loss ◽  
Stainless Steel Pipe ◽  
Loss Coefficients ◽  
Pvc Pipe ◽  
The Cross ◽  
Loss Effect

PVC pipe (polyvinyl chloride), galvanized, and stainless steel are types of pipes that are widely used, especially for delivering clean water to people's homes or in the industrialized world. This research was conducted by collecting data such as: flow rate (Q), pressure height (h), pipe flow velocity (v), time (s), and head loss (H), data were collected and calculated to determine pressure loss, effect variations in discharge changes and loss coefficients. From the experimental results, it was found that for the narrowing of the cross section at a discharge of 25 liters / second the value of the head loss was greater, which was located in the galvanic pipe, namely 0.09568, then followed by a discharge of 20 liters / second the value was 0.06454 and a discharge of 15 ltr / second the value was 0 , 03723. While the smallest value in panampang narrowing lies in PVC pipe, at a discharge of 25 ltr / second the value is 0.05957, at a discharge of 20 ltr / second the value is 0.03989 and at a discharge of 15 ltr / second the value is 0.02303. Likewise in the expansion of the cross-section, the greatest value lies in the galvanized pipe. For a debit of 25 ltr / second the value obtained is 0.03526, a debit of 20 ltr / second the value is 0.02355, a debit of 15 ltr / second the value is 0.01352. While the smallest value is located on the stainless steel pipe, the value is 0.02688 for the flow rate of 25 liters / second, the value for 20 liters / second is 0.01811, the value for 15 liters / second is 0.01044.

Springback law of high-strength 21-6-9 stainless steel tube in numerical control bending under different process parameters

2015 ◽  
Vol 231 (10) ◽  
pp. 1783-1792 ◽  
Author(s):  
Jun Fang ◽  
Shiqiang Lu ◽  
Kelu Wang ◽  
Zhengjun Yao
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Cross Section ◽  
Process Parameters ◽  
High Strength ◽  
Steel Tube ◽  
Numerical Control ◽  
Stainless Steel Tube ◽  
Outer Diameter ◽  
The Cross

In order to achieve the precision bending deformation, the effects of process parameters on springback behaviors should be clarified preliminarily. Taking the 21-6-9 high-strength stainless steel tube of 15.88 mm × 0.84 mm (outer diameter × wall thickness) as the objective, the multi-parameter sensitivity analysis and three-dimensional finite element numerical simulation are conducted to address the effects of process parameters on the springback behaviors in 21-6-9 high-strength stainless steel tube numerical control bending. The results show that (1) springback increases with the increasing of the clearance between tube and mandrel Cm, the friction coefficient between tube and mandrel fm, the friction coefficient between tube and bending die fb, or with the decreasing of the mandrel extension length e, while the springback first increases and then remains unchanged with the increasing of the clearance between tube and bending die Cb. (2) The sensitivity of springback radius to process parameters is larger than that of springback angle. And the sensitivity of springback to process parameters from high to low are e, Cb, Cm, fb and fm. (3) The variation rules of the cross section deformation after springback with different Cm, Cb, fm, fb and e are similar to that before springback. But under same process parameters, the relative difference of the most measurement section is more than 20% and some even more than 70% before and after springback, and a platform deforming characteristics of the cross section deformation is shown after springback.

scholarly journals Simulation of local head loss of drip-irrigation tape with integrated in-line emitters as a function of cross section

2020 ◽  
Vol 18 (4) ◽  
pp. e0210
Author(s):  
Yalin Wang ◽  
Xueliang Ju ◽  
Shijiang Zhu ◽  
Meng Li
Keyword(s):  
Cross Section ◽  
Drip Irrigation ◽  
Low Pressure ◽  
Head Loss ◽  
Three Gorges ◽  
Cross Sectional ◽  
Water Conservancy ◽  
The Cross ◽  
Sectional Shape ◽  
The Relationship

Aim of study: To investigate how the cross section of a drip-irrigation tape affects local head loss.Area of study: The work was carried out in the laboratory of Irrigation hydraulics, College of Water Conservancy and Environment, Three Gorges University, Yichang, Hubei province.Material and methods: Tapes with six different wall thicknesses were studied experimentally to determine the relationship between cross-section deformation, wall thickness, and pressure. Based on the experimental results, we determined the factors that influence local head loss in drip-irrigation tapes by numerical simulation and dimensional analysis.Main results: The cross-sectional shape of the drip-irrigation tape varied with pressure: under low pressure, the cross section was nearly elliptical. The cross-sectional shape of the tape strongly influenced the local head loss, which was inversely proportional to the 0.867th power of the flattening coefficient of the drip irrigation tape. We expressed the local head loss of a drip-irrigation tape equipped with integrated in-line emitters by considering the deformation of the cross section. Under the conditions used in this study, when the cross section is circular, the ratio of local head loss to frictional head loss was about 10% but, when the cross section is elliptical, this ratio increased to 15%.Research highlights: The shape of the cross section of a drip-irrigation tape is nearly elliptical under low pressure. Local head loss is inversely proportional to the 0.867th power of that is the flatting coefficient of the drip-irrigation tape. Local head loss is about 1.5 times for elliptical tape than circular tape.

Performance Evaluation of the Flow in Micro Junctions: Head Change Versus Head Loss Coefficients

2013 ◽  
Author(s):  
Bastian Schmandt ◽  
Heinz Herwig
Keyword(s):  
Energy Transfer ◽  
Mass Flow Rate ◽  
Entropy Generation ◽  
Mass Flow ◽  
Flow Rate ◽  
Head Loss ◽  
Total Head ◽  
Single Mass ◽  
Flow Through ◽  
Loss Coefficients

Losses due to the flow through conduit components in a pipe system can be characterised by head loss coefficients. They basically account for the dissipation in the flow field or, in a more general sense, for the entropy generation due to the conduit component under consideration. When only one single mass flow rate is involved, an entropy based approach is straight forward and ṁ can be used as a general reference quantity. If, however, the mass flow rate is split or united like in junctions, some new aspects appear. In our study the general approach for these kind of conduit components is discussed. Like for single mass flow rates losses are accounted for by determining the entropy generation rates. New aspects for the branched flows are an additional parameter, the splitting ratio, and the fact that there is an energy transfer between the single branches that has to be accounted for appropriately. It turns out that this energy transfer changes the total head in each flow brach in addition to a sole loss of total head. Therefore, the coefficients should be named head change coefficients when this effect occurs. As an example the flow through a T-shaped junction is considered, for which head loss coefficients are determined for both branches and discussed with respect to their physical meaning.

scholarly journals Integral Thermo-Anemometers for Average Temperature and Airflow Measurement in Ducts, at Anemostat Outlets and in Ventilation Grilles

2020 ◽  
Vol 23 (4) ◽  
pp. 14-21
Author(s):  
Oleh S. Tsakanian ◽  
◽  
Serhii V. Koshel ◽  
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Air Flow ◽  
Hot Wire ◽  
Air Flow Rate ◽  
National Academy Of Sciences ◽  
Calibration Dependence ◽  
The Cross ◽  
And Control ◽  
Ventilation Systems

When creating ventilation systems, it is important to correctly calculate the volumes of air inflow and outflow. If an error is made in the calculation or a redistribution of air flows is required, measurements are indispensable. The existing methods for determining the air flow rate by using point measurements in the cross-section are laborious and time-consuming, and taking readings at different time points introduces a significant error into the result. A. M. Pidhornyi Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine has developed a new hot-wire anemometer whose use greatly simplifies the measuring process. This device allows one to measure the average values of temperature and air velocity (flow rate) in the cross-section of air ducts or at the inlets and outlets of grilles and anemostats, and can be used in real time to monitor and control air flow rate and temperature in ventilation systems. The probe of the hot-wire anemometer is a metal shell with guides on which a sensitive element is laid. Its principle of operation is to change the heat transfer coefficient at different air leakage velocities. The anemometer is preliminarily calibrated in laboratory conditions at various velocities. There has been obtained a calibration dependence that can be used to measure the air flow rate at the inlets and outlets of air distribution devices and directly in the air ducts. To improve the measurement accuracy, it is necessary to provide the 90° angle of airflow leakage on the hot-wire anemometer probe. For this, special air collectors and air flow rectifiers are used.

scholarly journals Head Loss Reduction in Surcharged Four-Way Junction Manholes

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1741 ◽  
Author(s):  
Jung Kim ◽  
Jun Jo ◽  
Sei Yoon
Keyword(s):  
Numerical Simulations ◽  
Physical Model ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Head Loss ◽  
Loss Reduction ◽  
Effluent Flow Rate ◽  
Loss Coefficients ◽  
Drainage Capacity ◽  
Influent Flow

Head loss in surcharged four-way junction manholes is a factor that increases damage due to urban inundation; thus, the flow characteristics of such manholes must be analyzed to reduce the head loss. In this study, a physical model was constructed; this model included a manhole and a connection pipe, fabricated on a 1/5 scale by applying sewer facility standards to perform a physical model investigation. Numerical simulations were performed using the Fluent model to derive efficient benching designs that can reduce head loss. Physical model investigations were performed by varying the ratio of the lateral influent flow rate to the effluent flow rate as well as by varying the effluent flow rate and benching designs. The result of physical model investigations showed that the installation of half rectangular benching reduced the head loss coefficients by 7% and 10% on average compared with square and circular manholes, respectively. The installation of full rectangular benching reduced the head loss coefficients by 28% and 17% on average compared with square and circular manholes, respectively. Thus, the benching proposed herein can be installed and used to improve the drainage capacity of urban stormwater conduit facilities.

Study on Micro Valve Using Micro Fluidic Device and Zero-Net-Flow-Rate Micro Jet

2007 ◽  
Author(s):  
Yasuo Koizumi ◽  
Hiroyasu Ohtake
Keyword(s):  
Reynolds Number ◽  
Cross Section ◽  
Flow Rate ◽  
Piezoelectric Element ◽  
Test Fluid ◽  
Commercial Code ◽  
Fluidic Device ◽  
The Cross

Characteristics of a mini/micro-size Y-type fluidic device were examined using water as test fluid. The cross-section of an inlet path and outlet branches was 1 mm × 1 mm square. That of signal ports was 1 mm × 0.5 mm. Although Reynolds number tested was low; less than 1000, the mini/micro-size fluidic device functioned as the fluidic device; flow provided for a signal port flowed out from an opposite outlet. It was also analytically proved by the commercial code of STAR-CD. A zero-net flow micro-jet which had been analytically predicted was experimentally confirmed. A piezoelectric element was used to produce the zero-net flow micro-jet. A new concept of the mini/micro-size fluidic device was proposed. In that design, the signal ports were replaced with the zero-net flow micro-jet which was formed by the piezoelectric element. It was confirmed that the new design would function as the fluidic device.

scholarly journals Structural Behaviour and Fire Design of Duplex and Ferritic Stainless Steel CHS Stub Columns

2021 ◽  
Author(s):  
Asif Mohammed ◽  
Katherine A. Cashell
Keyword(s):  
Stainless Steel ◽  
Cross Section ◽  
Ferritic Stainless Steel ◽  
Material Model ◽  
Numerical Approach ◽  
Structural Behaviour ◽  
Cross Sectional ◽  
Hardening Material ◽  
The Cross ◽  
Stub Columns

AbstractThis paper investigates the structural behaviour and design of duplex and ferritic stainless steel stub columns with a circular hollow cross-section (CHS) at elevated temperature. A numerical model is developed to supplement the limited test results on stainless steel CHS stub columns in the literature. Following validation, the numerical approach is employed to gain an understanding of the critical behavioural characteristics which have not previously been studied. In addition, the paper considers and extends the continuous strength method (CSM) to include duplex and ferritic stainless steel for CHS stub columns in fire. The CSM employs a base curve linking the cross-section resistance to its deformation capacity and implements an elastic, linear hardening material model. The cross-sectional resistances obtained from the proposed CSM are compared with those from the numerical analysis, as well as with the standardised procedures in the European, American and Australia/New Zealand design standards. It is demonstrated that CSM can lead to more accurate and less scattered strength predictions than current design codes.

scholarly journals Friction evaluation of an elastic chain positioned under or over the wire in self-ligating brackets

2021 ◽  
Vol 11 ◽  
pp. 183-190
Author(s):  
Rodrigo Romano da Silva ◽  
Graziane Olímpio Pereira ◽  
Soraia Macari ◽  
Jurandir Antonio Barbosa ◽  
Roberta Tarkany Basting
Keyword(s):  
Stainless Steel ◽  
Cross Section ◽  
Frictional Resistance ◽  
Steel Wires ◽  
Acrylic Plate ◽  
The Wire ◽  
The Cross ◽  
Elastomeric Chains

Objectives: This study aimed to evaluate the frictional resistance produced by active and passive self-ligating brackets on stainless steel archwires in the absence or presence of elastomeric chains under or over the wire. Materials and Methods: Four types of self-ligating brackets were used: Two active and two passive. For each commercial brand, five brackets were bonded to an acrylic plate and the frictional resistance was evaluated with 0.018” and 0.019” × 0.025” stainless steel wires in three situations: Without elastomeric chain, with elastomeric chain placed under and over the wire. Results: The bracket type, cross-section of the wire, and type of ligation had significant interactions with each other; the frictional resistance was significantly lower with the use of passive self-ligated brackets, while no difference was found when a 0.018” wire was tested. Moreover, the frictional resistance in the absence of an elastomeric chain, or when the chain was under the wire, was significantly lower in comparison with the values obtained when the chain was placed on the wire. Conclusion: Frictional resistance of passive and active self-ligated brackets is influenced by the ligation methods and the cross-sectioning of archwires.

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