Prediction of Flow Path Pressure Drops in Curved Galleries for Additively Manufactured Hydraulic Manifolds

2021 ◽  
Author(s):  
L. D. Hashan Peiris ◽  
Andrew Plummer ◽  
Jens Roesner ◽  
Vimal Dhokia ◽  
Wesley Essink
Keyword(s):  
Pressure Drop ◽  
Flow Path ◽  
Bend Angle ◽  
Flow Paths ◽  
Pressure Drops ◽  
Form Pressure ◽  
Manifold Optimization ◽  
Computational Fluid Dynamics Cfd ◽  
Sharp Corners ◽  
Analytical Expressions

Abstract Hydraulic manifolds are traditionally manufactured using externally drilled intersecting galleries. This results in undesirable artefacts in the flow path such as sharp corners, and dead oil volumes, and requires additional plugs to blank redundant holes. These artefacts affect flow separation, aggravate pressure-drop and reduce hydraulic stiffness. Recent advancements in additive manufacturing (AM) technology have enabled the development of additively manufactured components which provide greater freedom in channel design and routing. Galleries can provide flow paths which are smoothly curved in 3 dimensions. AM manifold geometry can be optimized to reduce size and weight. In this research, analytical expressions are sought to approximate pressure drops in complex curved flow paths, which can subsequently be used for manifold optimization. The curved flow paths are defined by polynomial splines which are then fragmented into a series of segments each defined by a bend angle and bend radius. This paper uses approximations to Computational Fluid Dynamics (CFD) results to form pressure-drop models over a range of segment bend radii and angles. These models are then used to predict the pressure drops for curved galleries used in AM manifolds. The method is applied to four example curved galleries, and provides a reasonably accurate pressure-drop prediction in each case.

Effect of Blade Numbers on Pressure Drop of Axial Cyclone Separators by CFD

2011 ◽  
Vol 55-57 ◽  
pp. 343-347 ◽  
Author(s):  
Yi Gang Luan ◽  
Hai Ou Sun
Keyword(s):  
Pressure Drop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Three Dimensional Model ◽  
Navier Stokes Equations ◽  
Pressure Drops ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Resistance Performance

In this article, computational fluid dynamics(CFD) method is used to predict the effect of blade numbers on the pressure drop of axial cyclone separators. A three-dimensional model is built to acquire the resistance of axial cyclone separators with different blade numbers. The flow field inside cyclone separators is calculated using 3D Reynolds-averaged Navier-Stokes equations. And turbulence model is used to simulate the Reynold stress. Also pressure drop of cyclone separators with different blade numbers is expressed as a function of different inlet velocities. At the same inlet velocity with increasing the blade numbers, pressure drops of cyclones reduce greatly. And changing the blade number of cyclone separator is an effective method to improve its resistance performance.

Numerical Investigation of Dusts Removal from Tramway Surface by Street Vacuum Sweeper

2011 ◽  
Vol 236-238 ◽  
pp. 1619-1622 ◽  
Author(s):  
Bo Fu Wu ◽  
Jin Lai Men ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
Pressure Drops ◽  
Operational Safety ◽  
Airflow Field ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

In order to enhance the operational safety of tram vehicle and reduce the wear of guide wheels mounted on the vehicle, it is necessary to remove particles such as dusts and silts from tramway surface. The aim of this paper is to evaluate the effectiveness of street vacuum sweeper for sucking up dusts from tramway surface. A numerical model was developed based on dusts removal process. Under different pressure drops across the pickup head of the street vacuum sweeper, the flow field and dusts removal efficiency were analyzed with computational fluid dynamics (CFD) method. The numerical results show that a higher pressure drop can improve the airflow field in the pickup head and results in higher dusts removal efficiency, but higher pressure drop definitely need more energy. Therefore, a balance should be taken into consideration.

scholarly journals Effect of Modification in Flow Distributor Valve Geometry on the Pressure Drop and Chamber Pressures, in Numerical and Analytical Way, in ORBIT Motor HST Unit

2018 ◽  
Author(s):  
Debanshu Roy ◽  
Amit Kumar ◽  
Rathindranath Maiti ◽  
Prasanta Kumar Das
Keyword(s):  
Mathematical Model ◽  
Pressure Drop ◽  
Cfd Analysis ◽  
Pressure Drops ◽  
Comprehensive Knowledge ◽  
Flow Interactions ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Spool Valve ◽  
Flow Distributor

In this paper, an attempt has been made to analyze the effect of spool port/ groove geometry on the pressure drop and chamber pressures which effect the performance parameters of the flow distributor valve. The work mainly involves formulation of detailed mathematical model of the valve and compare them on the same platform. For mathematical modelling, Matlab has been used. The size of the orifices is considered same throughout the model for better comparison. Initially the construction and functioning of flow distributor valve along with working principles of hydrostatic motor (Rotary Piston) is shown. Next shown the analytical analysis of area change and pressure drops due to different geometry of the spool valve ports. After that the computational fluid dynamics (CFD) analysis has been shown. A complete mathematical model to describe such flow distributor valve is developed after having a comprehensive knowledge of orifice characteristics, flow interactions based on valve geometry. Equations of flow through different orifices (fixed and variable area) of the valve have been developed based on the relationships obtained earlier.

scholarly journals CFD Analysis of Non-Newtonian Pseudo Plastic Liquid Flow through Bends

2017 ◽  
Vol 61 (3) ◽  
pp. 184 ◽  
Author(s):  
Suman Debnath ◽  
Tarun Kanti Bandyopadhyay ◽  
Apu Kumar Saha
Keyword(s):  
Pressure Drop ◽  
Liquid Flow ◽  
Static Pressure ◽  
Methyl Cellulose ◽  
Bend Angle ◽  
Frictional Pressure Drop ◽  
Fluid Behavior ◽  
Diameter Pipe ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

Non-Newtonian pseudo plastic liquid flow through different types of 0.0127 m diameter pipe bends as well as straight pipe have been investigated experimentally to evaluate frictional pressure drop across the bends in laminar and water flow in turbulent condition. We have studied here the effect of flow rate, bend angle, fluid behavior on static pressure and pressure drop. A Computational Fluid Dynamics (CFD) based software is used to predict the static pressure, pressure drop, shear stress, shear strain, flow structure, friction factor, loss co- efficient inside the bends for Sodium Carboxy Methyl Cellulose (SCMC) solution as a non-Newtonian pseudo plastic fluids and water as a Newtonian fluid. Laminar Non-Newtonian pseudo plastic Power law model is used for SCMC solution to numerically solve the continuity and the momentum equations. The experimental data are compared with the CFD generated data and is well matched. The software predicted data may be used to solve any industrial problem and also to design various equipment.

Numerical Analysis on the Impact of Interstage Flow Addition in a High-Pressure Steam Turbine

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Soo Young Kang ◽  
Jeong Jin Lee ◽  
Tong Seop Kim ◽  
Seong Jin Park ◽  
Gi Won Hong
Keyword(s):  
High Pressure ◽  
Pressure Drop ◽  
Computational Analysis ◽  
Fluid Dynamic ◽  
Geometric Model ◽  
Flow Path ◽  
Complex Flow ◽  
Flow Paths ◽  
Single Passage ◽  
The Impact

This study analyzes the fluid dynamic characteristics of an ultrasupercritical (USC) high-pressure turbine with additional steam supplied through an overload valve between the second and third stages. The mixing between the main and admission flows causes complex flow phenomena such as swirl and changes of velocity vectors of the main flow. This causes a pressure drop between the second-stage outlet and third-stage inlet, which could potentially affect the performance of the turbine. First, a single-passage computational analysis, which is usually preferred in predicting the performance of multistage turbomachines, was performed using a simple model of an admission flow path and a single passage (SP) for the second and third stages of the turbine. However, the actual flow in the overload valve is supplied through the admission flow path, which has the shape of a casing that circumferentially surrounds the turbine, after flowing in two directions perpendicular to the turbine axis. This necessitates full-passage computational analyses of the two stages and the flow paths of the admission flow. To achieve this, we implemented a full three-dimensional (3D) geometric model of the admission flow path and conducted a full-passage computational analysis for all the flow paths, including those of the second and third stages of the turbine. The focus of analysis was on the pressure drop due to the admission flow. The results of the single and full-passage analyses were compared, and the effects of two different methods were analyzed.

scholarly journals Effects of Raschig Ring Packing Patterns on Pressure Drop, Heat Transfer, Methane Conversion, and Coke Deposition on a Semi-pilot-scale Packed Bed Reformer

2019 ◽  
Vol 33 (2) ◽  
pp. 191-211
Author(s):  
Nattaporn Chutichairattanaphum ◽  
Karn Pana-Suppamassadu ◽  
Worawat Wattanathana ◽  
Siwaruk Chotiwan ◽  
Chaiwat Prapainainar ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Methane Conversion ◽  
Packed Bed ◽  
Pilot Scale ◽  
Coke Deposition ◽  
Pressure Drops ◽  
Raschig Ring ◽  
Reactor Length ◽  
Computational Fluid Dynamics Cfd ◽  
Reforming Reactions

The effects of Raschig ring packing patterns on the efficiency of dry methane reforming reactions were investigated using computational fluid dynamics (CFD). The present study aims to understand the behavior of fluid flow in packed bed reactors, especially under low reactor-to-ring ratios between 4 and 8. Three packing patterns were studied: vertical staggered (VS), chessboard staggered (CS), and reciprocal staggered (RS). It was determined that packing pattern notably affected pressure drop across the reactor length. The VS pattern produced the lowest pressure drop of 223 mPa, while the CS and RS patterns produced pressure drops of 228 mPa and 308 mPa, respectively. The values of methane conversion can be increased by ca. 2 % by selecting a more suitable packing pattern (i.e., 76 % for the VS pattern and 74 % for the CS and RS patterns).

Experimental and Computational Analyses of Pressure Differentials in Flexible Ducts With Different Bent Angles

2007 ◽  
Author(s):  
Ray R. Taghavi ◽  
Wonjin Jin ◽  
Mario A. Medina
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Complex Geometry ◽  
Analysis Data ◽  
Secondary Flows ◽  
Low Flow ◽  
Pressure Drops ◽  
Pressure Distributions ◽  
Geometrical Effects ◽  
Cfd Analyses

A set of experimental analyses was conducted to determine static pressure drops inside non-metallic flexible, spiral wire helix core ducts, with different bent angles. In addition, Computational Fluid Dynamics (CFD) solutions were performed and verified by comparing them to the experimental data. The CFD computations were carried out to produce more systematic pressure drop information through these complex-geometry ducts. The experimental setup was constructed according to ASHRAE Standard 120-1999. Five different bent angles (0, 30, 45, 60, and 90 degrees) were tested at relatively low flow rates (11 to 89 CFM). Also, two different bent radii and duct lengths were tested to study flexible duct geometrical effects on static pressure drops. FLUENT 6.2, using RANS based two equations - RNG k-ε model, was used for the CFD analyses. The experimental and CFD results showed that larger bent angles produced larger static pressure drops in the flexible ducts. CFD analysis data were found to be in relatively good agreement with the experimental results for all bent angle cases. However, the deviations became slightly larger at higher velocity regimes and at the longer test sections. Overall, static pressure drop for longer length cases were approximately 0.01in.H2O higher when compared to shorter cases because of the increase in resistance to the flow. Also, the CFD simulations captured more pronounced static pressure drops that were produced along the sharper turns. The stronger secondary flows, which resulted from higher and lower static pressure distributions in the outer and inner surfaces, respectively, contributed to these higher pressure drops.

Experimental Study of Evaporation Heat Transfer Characteristics and Pressure Drops of R410A and R134a in a Multiport Mini-Channel

2009 ◽  
Author(s):  
Jatuporn Kaew-On ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Transfer Coefficients ◽  
Pressure Drops ◽  
Heat Transfer Coefficients ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer ◽  
R 134A

The evaporation heat transfer coefficients and pressure drops of R-410A and R-134a flowing through a horizontal-aluminium rectangular multiport mini-channel having a hydraulic diameter of 3.48 mm are experimentally investigated. The test runs are done at refrigerant mass fluxes ranging between 200 and 400 kg/m2s. The heat fluxes are between 5 and 14.25 kW/m2, and refrigerant saturation temperatures are between 10 and 30 °C. The effects of the refrigerant vapour quality, mass flux, saturation temperature and imposed heat flux on the measured heat transfer coefficient and pressure drop are investigated. The experimental data show that in the same conditions, the heat transfer coefficients of R-410A are about 20–50% higher than those of R-134a, whereas the pressure drops of R-410A are around 50–100% lower than those of R-134a. The new correlations for the evaporation heat transfer coefficient and pressure drop of R-410A and R-134a in a multiport mini-channel are proposed for practical applications.

Heat Transfer and Pressure Drop in a Converging Pedestal Array With Exit Area Variation

2018 ◽  
Author(s):  
L. W. Soma ◽  
F. E. Ames ◽  
S. Acharya
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Rate ◽  
Film Cooling ◽  
Reynolds Numbers ◽  
Flow Path ◽  
Internal Cooling ◽  
Channel Measurements ◽  
Trailing Edge ◽  
Cooling Air

The trailing edge of a vane is one of the most difficult areas to cool due to a narrowing flow path, high external heat transfer rates, and deteriorating external film cooling protection. Converging pedestal arrays are often used as a means to provide internal cooling in this region. The thermally induced stresses in the trailing edge region of these converging arrays have been known to cause failure in the pedestals of conventional solidity arrays. The present paper documents the heat transfer and pressure drop through two high solidity converging rounded diamond pedestal arrays. These arrays have a 45 percent pedestal solidity. One array which was tested has nine rows of pedestals with an exit area in the last row consistent with the convergence. The other array has eight rows with an expanded exit in the last row to enable a higher cooling air flow rate. The expanded exit of the eight row array allows a 30% increase in the coolant flow rate compared with the nine row array for the same pressure drop. Heat transfer levels correlate well based on local Reynolds numbers but fall slightly below non converging arrays. The pressure drop across the array naturally increases toward the trailing edge with the convergence of the flow passage. A portion of the cooling air pressure drop can be attributed to acceleration while a portion can be attributed to flow path losses. Detailed array static pressure measurements provide a means to develop a correlation for the prediction of pressure drop across the cooling channel. Measurements have been acquired over Reynolds numbers based on exit flow conditions and the characteristic pedestal length scale ranging from 5000 to over 70,000.

Swirling Annular Flow in a Steam Separator

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Hironobu Kataoka ◽  
Yusuke Shinkai ◽  
Shigeo Hosokawa ◽  
Akio Tomiyama
Keyword(s):  
Pressure Drop ◽  
Annular Flow ◽  
Nuclear Reactor ◽  
Water Pressure ◽  
Interfacial Friction ◽  
Pressure Drops ◽  
Pressure Transducers ◽  
Ring Configuration ◽  
Film Flows ◽  
Steam Separator

Effects of pick-off ring configuration on the separator performance of a downscaled model of a steam separator for a boiling water nuclear reactor are examined using various types of pick-off rings. The experiments are conducted using air and water. Pressure drops in a barrel and a diffuser and diameters and velocities of droplets at the exit of the barrel are measured using differential pressure transducers and particle Doppler anemometry, respectively. The separator performance does not depend on the shape of the pick-off ring but strongly depends on the width of the gap between the pick-off ring and the barrel wall. The pressure drop in the barrel is well evaluated using the interfacial friction factor for unstable film flows. Carry-under can be estimated using a droplet velocity distribution at the exit of the separator.

Sign in / Sign up

Export Citation Format

Share Document