Numerical Simulation of Flow in Imported Steam Turbine Inlet Components with Equilibrated Holes in High Performance

2013 ◽  
Vol 712-715 ◽  
pp. 1263-1267
Author(s):  
Shan Tu ◽  
Shu Ming Wu ◽  
Qi Zhou ◽  
Hong Mei Zhang ◽  
Xiao Qing Zhu
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
High Performance ◽  
Optimization Design ◽  
Great Influence ◽  
Control Valve ◽  
Stable Operation ◽  
Valve Seat ◽  
Valve Disc ◽  
Interior Flow

The main inlet component of steam turbine is control valve. The stable operation of the steam turbine control valve is vital for safe and stable operation of the steam turbine and safety production of the power plant. However, due to the complexity of the structure and unsteady characteristics of steam flow in the valve, there is not enough experimental method about the detailed flow characteristics of the area near control valve disc and the inside of the valve chamber up to now. This article is to focus on the simulation of the steam turbine control valve interior flow field which includes the valve pre-inlet channel in different conditions, then find the reasons which caused instability and pressure loss of the control valve by analyzing the flow field details, finally further optimization design. The profile matching of the valve disc and valve seat has a great influence on the interior flow field of control valve, so analysis of the high performance valve disc shape and divergence angle of valve seat is carried out, and the research conclusion is used for guide design and development of the control valve.

Numerical Simulation of Interior Flow in Evaporation Droplet

2014 ◽  
Author(s):  
Qingming Dong ◽  
Zhentao Wang ◽  
Yonghui Zhang ◽  
Junfeng Wang
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Internal Flow ◽  
Surface Force ◽  
Droplet Surface ◽  
Force Model ◽  
Marangoni Flow ◽  
High Temperature Area ◽  
Interior Flow ◽  
Temperature Area

In this present study, the VOF (Volume of Fluid) approach is adopted to capture the interface, and CSF (Continuum Surface Force) model to calculate the surface tension, and the governing equations are founded in numerical simulation of evaporating droplets. In this work, a water droplet is assumed to be suspending in high temperature air, and the gravity of a droplet is ignored. During evaporating process of the droplet, the internal circulation flow will be induced due to the gradient of temperature at the droplet surface. The interface flows from high temperature area to low temperature area, which pulls the liquid to produce convective flow inside the droplet called as Marangoni flow. Marangoni flow makes the temperature distribution tend to uniformity, which enhances heat transfer but weakens Marangoni flow in turn. So, during droplet evaporation, the internal flow is not steady.

The Range of Jupiter's Flow Structures that Fit the Juno Asymmetric Gravity Measurements

2021 ◽  
Author(s):  
Keren Duer ◽  
Eli Galanti ◽  
Yohai Kaspi
Keyword(s):  
Gravity Data ◽  
Microwave Radiometer ◽  
Jet Streams ◽  
Zonal Jets ◽  
Flow Profiles ◽  
Gravity Measurements ◽  
Interior Flow ◽  
Dependent Flow ◽  
Meridional Profile ◽  
Wind Profiles

<p>The asymmetric gravity field measured by the Juno spacecraft has allowed the estimation of the depth of Jupiter's zonal jets, showing that the winds extend approximately 3,000 km beneath the cloud level. This estimate was based on an analysis using a combination of all measured odd gravity harmonics, <em>J</em><sub>3</sub>, <em>J</em><sub>5</sub>, <em>J</em><sub>7</sub>, and <em>J</em><sub>9</sub>, but the wind profile's dependence on each of them separately has yet to be investigated. Furthermore, these calculations assumed the meridional profile of the cloud‐level wind extends to depth. However, it is possible that the interior jet profile varies somewhat from that of the cloud level. Here we analyze in detail the possible meridional and vertical structure of Jupiter's deep jet streams that can match the gravity measurements. We find that each odd gravity harmonic constrains the flow at a different depth, with <em>J</em><sub>3</sub> the most dominant at depths below 3,000 km, <em>J</em><sub>5</sub> the most restrictive overall, whereas <em>J</em><sub>9</sub> does not add any constraint on the flow if the other odd harmonics are considered. Interior flow profiles constructed from perturbations to the cloud‐level winds allow a more extensive range of vertical wind profiles, yet when the meridional profiles differ substantially from the cloud level, the ability to match the gravity data significantly diminishes. Overall, we find that while interior wind profiles that do not resemble the cloud level are possible, they are statistically unlikely. Finally, inspired by the Juno microwave radiometer measurements, assuming the brightness temperature is dominated by the ammonia abundance, we find that depth‐dependent flow profiles are still compatible with the gravity measurements.</p>

A three-dimensional model of the wind-driven ocean circulation

1968 ◽  
Vol 34 (4) ◽  
pp. 721-734 ◽  
Author(s):  
J. A. Johnson
Keyword(s):  
Ocean Circulation ◽  
Three Dimensional ◽  
Ekman Layer ◽  
Return Flow ◽  
Western Boundary ◽  
Dimensional Model ◽  
Boundary Current ◽  
Three Dimensional Model ◽  
Wind Stress Curl ◽  
Interior Flow

A linear three-dimensional model of the wind-driven ocean circulation is treated by boundary-layer methods. The interior flow, below the Ekman layer, differs from the classical gyres of Munk (1950). There is a north-eastwards transport of fluid from the western boundary current of the southern gyre across the latitude of zero wind stress curl into the northern gyre. A return flow in the Ekman layer preserves continuity.

scholarly journals On-wall and interior separation in a two-fluid boundary layer

2019 ◽  
Vol 119 (1) ◽  
pp. 1-21
Author(s):  
Sergei N. Timoshin ◽  
Pallu Thapa
Keyword(s):  
Boundary Layer ◽  
Pressure Variation ◽  
Flow Reversal ◽  
Reversed Flow ◽  
Two Fluids ◽  
Transverse Pressure ◽  
Fluid Boundary ◽  
Interior Flow ◽  
High Reynolds ◽  
Two Fluid

Abstract A two-fluid boundary layer is considered in the context of a high Reynolds number Poiseuille–Couette channel flow encountering an elongated shallow obstacle. The flow is laminar, steady and two-dimensional, with the boundary layer shown to have the pressure unknown in advance and a specified displacement (a condensed boundary layer). The focus is on the detail of the flow reversal triggered by the obstacle. The interface between the two fluids passes through the boundary layer which, in conjunction with the effects of gravity and distinct densities in the two fluids, leads to several possible topologies of the reversed flow, including a conventional on-wall separation, interior flow reversal above the interface, and several combinations of the two. The effect of upstream influence due to a transverse pressure variation under gravity is mentioned briefly.

scholarly journals Transient simulation in interior flow field of lobe pump

2013 ◽  
Vol 52 (3) ◽  
pp. 032019
Author(s):  
Y B Li ◽  
X H Sang ◽  
Q W Meng ◽  
H Shen ◽  
K Jia
Keyword(s):  
Flow Field ◽  
Transient Simulation ◽  
Interior Flow ◽  
Lobe Pump

Interior Flow of a Vertical Jet Under Gravity

1970 ◽  
Vol 37 (2) ◽  
pp. 530-532 ◽  
Author(s):  
William E. Conway ◽  
Jack M. Bullock
Keyword(s):  
Interior Flow ◽  
Vertical Jet

Spiral Flow Capability Research in the Rotary Cylinder

2011 ◽  
Vol 103 ◽  
pp. 209-213
Author(s):  
Song Bai Li ◽  
Yi Lun Liu
Keyword(s):  
Flow Rate ◽  
Structural Design ◽  
Simple Algorithm ◽  
Inlet Pressure ◽  
Maximum Temperature ◽  
Radial Clearance ◽  
Interior Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Laminar Flow Model

In order to obtain the lubricating capabilityof screw rotary cylinder, its structural design and operation principle were introduced. Seven screw pairs with different radial clearance were designed. The models were built by Pro/E. Structure mesh was generated by using Gambit. Based on laminar flow model and SIMPLE algorithm, the interior flow field in different radial clearances and the same radial clearance at different inlet pressure were numerically simulated and analyzed with Fluent. The relationship of loading force, stiffness, maximum temperature, flow rate and radial clearance were obtained. Simulation results show that the performance of oil lubricated screw pair is the best at the radial clearance of 0.10 mm. At the same radial clearance, when back pressure is constant, with inlet pressure increasing, loading force, stiffness, flow rate and maximum temperature increase completely.

Simulation Analysis and Evaluation of Inner Airflow Characteristics on the 2.0L Di Engine

2013 ◽  
Vol 860-863 ◽  
pp. 1715-1719
Author(s):  
De Gang Li ◽  
Xiao Mei Han ◽  
Xue Dong Lin ◽  
Xiao Fang Luan ◽  
Le Zhang
Keyword(s):  
Combustion Chamber ◽  
Evaluation Method ◽  
Fuel Injection ◽  
Simulation Analysis ◽  
Concentration Field ◽  
Structure Design ◽  
Injection System ◽  
Common Rail System ◽  
Analysis And Evaluation ◽  
Interior Flow

In order to assess the rationality of the combustion chamber structure of 2.0L diesel engine equipped with high pressure common rail system, evaluation methods of the interior flow dynamic characteristics was put forward .And numerical simulation was carried out on the effect of different combustion chamber structure matching different fuel injection system parameters on the transient distribution of velocity field, concentration field, temperature field. The results show that: the suggested evaluation method in the combustion chamber structure design is reasonable; and for certain injection system, reasonable design and optimized combustion chamber structure parameters are used to organize air flow characteristic effectively. These are important measures to realize energy conservation and emission reduction on diesel engines.

scholarly journals A pancake droplet translating in a Hele-Shaw cell: lubrication film and flow field

2016 ◽  
Vol 798 ◽  
pp. 955-969 ◽  
Author(s):  
Lailai Zhu ◽  
François Gallaire
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Streamwise Vortex ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Symmetric Pair ◽  
Lubrication Film ◽  
Stagnation Points ◽  
Interior Flow ◽  
Hele Shaw Cell

We adopt a boundary integral method to study the dynamics of a translating droplet confined in a Hele-Shaw cell in the Stokes regime. The droplet is driven by the motion of the ambient fluid with the same viscosity. We characterize the three-dimensional (3D) nature of the droplet interface and of the flow field. The interface develops an arc-shaped ridge near the rear-half rim with a protrusion in the rear and a laterally symmetric pair of higher peaks; this pair of protrusions has been identified by recent experiments (Huerre et al., Phys. Rev. Lett., vol. 115 (6), 2015, 064501) and predicted asymptotically (Burgess & Foster, Phys. Fluids A, vol. 2 (7), 1990, pp. 1105–1117). The mean film thickness is well predicted by the extended Bretherton model (Klaseboer et al., Phys. Fluids, vol. 26 (3), 2014, 032107) with fitting parameters. The flow in the streamwise wall-normal middle plane is featured with recirculating zones, which are partitioned by stagnation points closely resembling those of a two-dimensional droplet in a channel. Recirculation is absent in the wall-parallel, unconfined planes, in sharp contrast to the interior flow inside a moving droplet in free space. The preferred orientation of the recirculation results from the anisotropic confinement of the Hele-Shaw cell. On these planes, we identify a dipolar disturbance flow field induced by the travelling droplet and its $1/r^{2}$ spatial decay is confirmed numerically. We pinpoint counter-rotating streamwise vortex structures near the lateral interface of the droplet, further highlighting the complex 3D flow pattern.

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