Numerical Simulation of Ventilation Characteristics in a Hydropower Station Spillway Tunnel with High Head and Large Discharge

2014 ◽  
Vol 926-930 ◽  
pp. 3527-3530
Author(s):  
Hong Qing Zhang ◽  
Yi Long Lou ◽  
Wei Ping Xing ◽  
Jun Jun Tan
Keyword(s):  
Wind Speed ◽  
Hydropower Station ◽  
Aerated Flow ◽  
Speed Distribution ◽  
Vof Model ◽  
High Head ◽  
Spillway Tunnel ◽  
The Right ◽  
Ventilation Hole ◽  
Large Discharge

High wind speedandloudnoise usually occur in the hydropower station spillway tunnel, which will impact the producing environment of operators. In this paper, turbulent model and VOF modelwere combinedto simulate wind speed and the volume of ventilated airin ventilation holeandthreeaeratorsin the spillway tunnel on the right bank of a hydropower station in China. The results show thatVOF modelcan well simulate ventilated air induced by water drag, andthe volume of ventilated air in ventilation hole is the largest.Wind speed distribution on the longitudinal sectionof the inlet of ventilation hole is non-uniform,and loud noisewill occurthere. Wind speed on the left side of three aerators is higher than that on the right side. The results of the volume of ventilated airin threeaerators simulated by VOF modelare credible, but we should improve the VOF model to more accurately simulate aerated flow.

Analysis the Response of Aerated Flow Depth to the VOF Model

2014 ◽  
Vol 716-717 ◽  
pp. 767-770
Author(s):  
Hong Qing Zhang ◽  
Yi Long Lou ◽  
Qian Zhao ◽  
Wei Kai Tan
Keyword(s):  
Water Depth ◽  
Empirical Formula ◽  
Maximum Deviation ◽  
Flow Depth ◽  
Turbulent Model ◽  
Aerated Flow ◽  
Vof Model ◽  
High Head ◽  
Spillway Tunnel ◽  
Large Discharge

In order to analysis the response of aerated flow depth to the VOF model, in this paper, we used VOF combining turbulent model to simulate aerated flow depth in a hydropower station spillway tunnel with high head and large discharge in China. The results show that aerated flow depth is slightly larger than the experiment water depth, but the maximum deviation are not greater than 5% (except the pile number 0+605.236 m). So, using empirical formula to converse the calculate value of water depth into aerated flow depth can make up for the defects of the VOF model which cannot directly get aerated flow depth of the cross section inside the spillway tunnel. But the section water depth can’t be obtained by empirical formula calculation value conversion when cavity exists in the spillway tunnel.

Comparative Analysis of Wind Speed in Ventilation Hole Simulated by VOF and Euler Model

2014 ◽  
Vol 624 ◽  
pp. 643-646
Author(s):  
Hong Qing Zhang ◽  
Xian Tang Zhang ◽  
Yi Long Lou ◽  
Wei Ping Xing
Keyword(s):  
Wind Speed ◽  
Outlet Section ◽  
Inlet Section ◽  
Two Phase ◽  
Vof Model ◽  
Wind Speed Distribution ◽  
Euler Model ◽  
Spillway Tunnel ◽  
Ventilation Hole ◽  
Large Discharge

In order to analysis the applicability of VOF and Euler models to simulate water-air two-phase flow, VOF model and Euler model, respectively combining turbulent model, were used to simulate wind speed in ventilation hole of working gate in a hydropower station spillway tunnel with high head and large discharge in China. The results show that the dragging force simulated by Euler model is much more effective than that simulated by VOF model, causing significant increase of airflow in ventilation hole. It is obviously that wind speed simulated by Euler model is more close to the measured one, which may also provide evidence for design of ventilation hole. So Euler model is a better method to simulate the characteristic of aerated flow than VOF model. Meanwhile, the maximum wind speed occur near the inlet of ventilation hole, and the maximum value of wind speed is close to 120 m/s, which can cause loud noise. And wind speed distribution on the inlet section and outlet section of ventilation hole is respectively the most non-uniform and uniform. The conclusions obtained can improve the design of ventilation hole.

Pressure Distribution of Pressure and Non-Pressure Sections of a Hydropower Station Spillway Tunnel

2014 ◽  
Vol 716-717 ◽  
pp. 244-247
Author(s):  
Hong Qing Zhang ◽  
Wei Kai Tan ◽  
Yi Long Lou ◽  
Qian Zhao
Keyword(s):  
Pressure Distribution ◽  
Model Experiment ◽  
Hydropower Station ◽  
Maximum Pressure ◽  
Turbulent Model ◽  
Sudden Drop ◽  
Sudden Enlargement ◽  
High Head ◽  
Spillway Tunnel ◽  
Large Discharge

In this paper, we used VOF combining turbulent model to simulate pressure distribution of pressure section and non-pressure section in a hydropower station spillway tunnel with high head and large discharge in China. The results show that in the pressure section of the spillway tunnel, the values of pressure of emergency gate slot, working gate and the pressing slope, getting from physical model experiment and numerical simulation, are all positive. While in the non-pressure section, the No.1、2、3 aerators of the sudden enlargement and sudden drop occur the maximum pressure. And at the back of the No.1、2、3 aerators, where the values of pressure are negative, forms cavity. The conclusions obtained can improve the design of spillway tunnel.

Study on Flow Characteristics inside a Spillway Tunnel of Hydropower Station

2014 ◽  
Vol 716-717 ◽  
pp. 219-222
Author(s):  
Hong Qing Zhang ◽  
Bing Cao ◽  
Yi Long Lou ◽  
Wei Kai Tan
Keyword(s):  
Flow Velocity ◽  
High Speed ◽  
Flow Characteristic ◽  
Flow Characteristics ◽  
Hydropower Station ◽  
Turbulent Model ◽  
Cross Sectional ◽  
Vof Model ◽  
Spillway Tunnel ◽  
The Right

VOF model and turbulent model were used in this paper to study on flow characteristic inside a certain spillway tunnel of hydropower station, which includes cross sectional distributions of flow velocity in pressure section and non-pressure section. The results show that flow velocity distribution in the pressure section of the spillway tunnel is basically symmetrical. After turning, flow velocity is well-distributed and move ahead; flow velocity in the right side of non-pressure section in the spillway tunnel is 1m/s faster than that in the left side. When two high-speed water flow come together after passing through the central division pier, flow velocity distributions in the both sides of the spillway tunnel are all uniform. The conclusions obtained can improve the design of the spillway tunnel.

Simulation and Experiments of Aerated Flow in Curve-Connective Tunnel with High Head and Large Discharge

2016 ◽  
Vol 14 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Shuai Li ◽  
Jian-min Zhang ◽  
Wei-lin Xu ◽  
Jian-gang Chen ◽  
Yong Peng ◽  
...  
Keyword(s):  
Aerated Flow ◽  
High Head ◽  
Large Discharge

scholarly journals Weibull Wind-Speed Distribution Parameters Derived from a Combination of Wind-Lidar and Tall-Mast Measurements Over Land, Coastal and Marine Sites

2015 ◽  
Vol 159 (2) ◽  
pp. 329-348 ◽  
Author(s):  
Sven-Erik Gryning ◽  
Rogier Floors ◽  
Alfredo Peña ◽  
Ekaterina Batchvarova ◽  
Burghard Brümmer
Keyword(s):  
Wind Speed ◽  
Speed Distribution ◽  
Wind Speed Distribution ◽  
Distribution Parameters ◽  
Wind Lidar

scholarly journals Observed Boundary Layer Wind Structure and Balance in the Hurricane Core. Part I: Hurricane Georges

2006 ◽  
Vol 63 (9) ◽  
pp. 2169-2193 ◽  
Author(s):  
Jeffrey D. Kepert
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Radial Profile ◽  
Lower Altitude ◽  
Near Surface ◽  
Wind Structure ◽  
The Right ◽  
Tropical Cyclone Boundary Layer ◽  
Upper Boundary

Abstract The GPS dropsonde allows observations at unprecedentedly high horizontal and vertical resolution, and of very high accuracy, within the tropical cyclone boundary layer. These data are used to document the boundary layer wind field of the core of Hurricane Georges (1998) when it was close to its maximum intensity. The spatial variability of the boundary layer wind structure is found to agree very well with the theoretical predictions in the works of Kepert and Wang. In particular, the ratio of the near-surface wind speed to that above the boundary layer is found to increase inward toward the radius of maximum winds and to be larger to the left of the track than to the right, while the low-level wind maximum is both more marked and at lower altitude on the left of the storm track than on the right. However, the expected supergradient flow in the upper boundary layer is not found, with the winds being diagnosed as close to gradient balance. The tropical cyclone boundary layer model of Kepert and Wang is used to simulate the boundary layer flow in Hurricane Georges. The simulated wind profiles are in good agreement with the observations, and the asymmetries are well captured. In addition, it is found that the modeled flow in the upper boundary layer at the eyewall is barely supergradient, in contrast to previously studied cases. It is argued that this lack of supergradient flow is a consequence of the particular radial structure in Georges, which had a comparatively slow decrease of wind speed with radius outside the eyewall. This radial profile leads to a relatively weak gradient of inertial stability near the eyewall and a strong gradient at larger radii, and hence the tropical cyclone boundary layer dynamics described by Kepert and Wang can produce only marginally supergradient flow near the radius of maximum winds. The lack of supergradient flow, diagnosed from the observational analysis, is thus attributed to the large-scale structure of this particular storm. A companion paper presents a similar analysis for Hurricane Mitch (1998), with contrasting results.

scholarly journals Numerical investigation of the fatal 1985 Manchester Airport B737 fire

2017 ◽  
Vol 121 (1237) ◽  
pp. 287-319 ◽  
Author(s):  
E. R. Galea ◽  
Z. Wang ◽  
F. Jia
Keyword(s):  
Wind Speed ◽  
Numerical Investigation ◽  
Computer Simulations ◽  
Potential Benefit ◽  
Fire Plume ◽  
Significant Difference ◽  
Actual Fire ◽  
The Right ◽  
The Impact ◽  
Burn Through

ABSTRACTIn this paper, fire and evacuation computer simulations are used to reconstruct the 1985 Manchester Airport B737 fire that resulted in the loss of 55 lives. First the actual fire and evacuation are reconstructed. Secondly, the impact of exit opening times and external wind on the fire and evacuation are investigated. Finally, the potential benefit offered by modern materials is evaluated. The results suggest that the number of fatalities could have been reduced by 87% had the forward right exit not malfunctioned and by 36% had the right over-wing exit been opened without delay. Furthermore, given the fuel pool size and location, a critical wind speed of 1.5m/s is necessary to cause the fire plume to lean onto the fuselage eventually resulting in fuselage burn-through. Finally, it is suggested that the use of modern cabin materials could have made a significant difference to the fire development and survivability.

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