Swept Blade Aerodynamics Numerical Simulation of Super-Critical HP Stage Static Cascade

2010 ◽  
Vol 29-32 ◽  
pp. 554-559
Author(s):  
Zi Ming Feng ◽  
Zhen Xu Sun ◽  
De Shi Zhang ◽  
Guang Ling Zhou ◽  
Chun Hong Li
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Secondary Flow ◽  
Low Energy ◽  
Sweep Angle ◽  
Blade Cascade ◽  
Flow Loss ◽  
Simulation Results ◽  
End Wall ◽  
Type Pressure

Super-critical HP steam stage static blade cascade is as the prototype blade to numerical simulations. Different swept blades are made by changing the sweep angle and sweep height in order to study the effect of swept blade on aerodynamics characteristics of turbine static cascade. The numerical simulation sweep angle are made of ±10° and 0°,swept heights are 30% blade height. The turbine aerodynamics characteristics are analyzed by NUMECA software. The numerical simulation results indicate: that aft-sweep blades negative C-type pressure distribution increase the low energy fluid centralizing in end-wall corner and the end-wall secondary flow loss, but the loss is decreased at mid-span, depending on the baseline. But fore-sweep blades C-type pressure distribution decrease the low energy fluid centralizing in endwall corner and the endwall secondary flow loss, but the loss is increased at mid-span, depending on the baseline.

Influence of Swept Wing on Axial Steam Turbine Static Cascade Aerodynamics

2008 ◽  
Author(s):  
Ziming Feng ◽  
Wanjin Han ◽  
Jingjun Zhong ◽  
Hongming Yan
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Secondary Flow ◽  
Steam Turbine ◽  
Static Pressure ◽  
Pressure Coefficient ◽  
Low Energy ◽  
Sweep Angle ◽  
High Pressure Stage ◽  
Flow Loss

Super-critical steam turbine high pressure stage static blade cascade is as the prototype blade to numerical simulations. The prototype blade has aft-loading and big front-edge radius characteristics. Different swept blades are made by changing the sweep angle and sweep height in order to study the effect of blade sweep on aerodynamic characteristics of super-critical steam turbine high pressure stage blade. The numerical simulation sweep angle are made of fore-angel 10°, 20°, 30° and aft-angle 10°, 20°, 30°, sweep height are made of 10%, 20%, 30% blade height. The steam turbine aerodynamics are analyzed such as static pressure coefficient of swept blade profiles, total pressure coefficient of swept blade at blade trailing edge, contour of mass averaged static pressure on meridional surface and velocity streamlines along hub and suction surface by CFD software CFX®. The numerical simulation results indicate the fore-swept blades increase the low energy fluid centralizing in endwall corner and the endwall secondary flow loss, but the loss is decreased at mid-span, comparing to the baseline. But aft-swept blades decrease the low energy fluid centralizing in endwall corner and the endwall secondary flow loss, but the loss is increased at mid-span, comparing to the baseline. Either the fore-sweep height or the aft-sweep angle can increase the above results. At the same time the swept blade aerodynamics also are computed at 10, −10 degree incidence, the results indicate it keep down the aft-loading characteristics of baseline.

Numerical Simulation of 3D Flow Field Structure in Turbine Cascade With Bowed Blades

2001 ◽  
Author(s):  
Songtao Wang ◽  
Zhongqi Wang ◽  
Guotai Feng
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pressure Gradient ◽  
Pressure Distribution ◽  
Great Influence ◽  
Horseshoe Vortex ◽  
Suction Surface ◽  
Blade Cascade ◽  
Passage Vortex ◽  
Type Pressure

The differences of flow field in bowed blade cascade and that in straight blade cascade are systematically studied in this paper. To bow a blade means to change its geometric boundary condition. This change not only affect the pressure distribution along the blade profile exit Mach number but also has great effect on the original position and development of the passage vertex. All of the changes mentioned above have great influence on the loss. Numerical simulation result showed that blade bowing can decrease the cross-pressure gradient near the end wall. This trend will be more obvious with the increase of the bow angle. The pressure gradient decrease is beneficial to weaken the passage vortex strength and reduces the secondary loss near the endwalls. In addition, Pressure gradient from endwalls to midspan can be established near suction surface in positively bowed blade. With the increase of bow angle, this C-type pressure distribution is remarkable. It is also found that this C-type pressure distribution will influence the position of corner vortex near the suction surface and will also influence the position and size of the passage vortex. Blade bowing also has great influence on the position of the saddle point near the leading edge and the separated line of the horseshoe vortex. It is found that the position of the saddle point and the separated line of both legs of the horseshoe vortex move forward in a positively bowed blade. The passage vortex structure in bowed cascade is also presented. It can be concluded that a bowed blade can make the passage vortex stable and helps change its structure from loose to compact. Blade bowing is also beneficial to limit the influence domain of the unstable passage vortex core by the stable limit cycle.

Growth of Secondary Flow Losses Downstream of a Turbine Blade Cascade

1985 ◽  
Author(s):  
L. D. Chen ◽  
S. L. Dixon
Keyword(s):  
Boundary Layer ◽  
Secondary Flow ◽  
Total Pressure ◽  
Turbine Cascade ◽  
Pressure Losses ◽  
Flow Losses ◽  
Blade Cascade ◽  
Flow Loss ◽  
Loss Coefficients ◽  
End Wall

End wall total pressure losses downstream of a low-speed turbine cascade have been measured at several planes in order to determine the changes in secondary flow loss coefficients and the growth of the mixing loss with distance downstream. The results obtained are compared with various published secondary flow loss correlations in an attempt to explain some of the anomalies which presently exist. The paper includes some new correlations including one for the important gross secondary loss coefficient YSG with loading and aspect ratio parameters as well as the upstream boundary layer parameters.

Influence of Surface Roughness on Turbine Nozzle Profile Loss and Secondary Loss

2006 ◽  
Author(s):  
Hisashi Matsuda ◽  
Fumio Otomo ◽  
Hiroyuki Kawagishi ◽  
Asako Inomata ◽  
Yoshiki Niizeki ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Secondary Flow ◽  
Total Pressure ◽  
Flow Region ◽  
Wall Roughness ◽  
Suction Surface ◽  
Flow Loss ◽  
End Wall ◽  
Profile Loss

The effects of surface roughness of both nozzle and end-wall on a turbine nozzle performance were investigated experimentally using liner cascade wind tunnel facility under the Reynolds number (Re) condition of Re = 0.3∼1.0 × 106. With buffing, milling, sand blasting and shot blasting, the total of seven levels of the model surface roughness were realized. In order to clarify the effect of the nozzle surface roughness on the profile loss, total pressure losses were measured using three-hole probe for different levels of the surface roughness. It became clear the nozzle profile loss increases as Reynolds number increases for larger roughness group. In addition, it appeared the profile loss depends on not only maximum value of the surface roughness but also roughness conditions. In order to examine the effect of surface roughness on the secondary flow loss, spatial total pressure field of the secondary flow region was measured using three-hole probe for the cases of smooth or rough nozzle surface with smooth or rough end-wall. The secondary flow structures were recognized at the 5∼10% span-wise height region of the suction surface of the nozzle for all cases. With increasing the nozzle surface roughness, not only the profile loss but also net secondary flow loss increases, which is defined as the difference between the total pressure loss and the profile loss in the secondary flow region. However, increase of the end-wall roughness has higher effect on the net secondary flow loss increase. Difference of the effect between the nozzle surface roughness and the end-wall roughness on the nozzle secondary flow loss was discussed.

Characteristics of Decompression Tank Internally Pressurized with Water Using OpenFOAM

2016 ◽  
Vol 836 ◽  
pp. 3-8 ◽  
Author(s):  
Syamsuri
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Numerical Simulations ◽  
Pressure Distribution ◽  
Small Area ◽  
Water Storage ◽  
Storage Tanks ◽  
Velocity Magnitude ◽  
Independent Test ◽  
Simulation Results

Decompression tank is a tank in which pressurized with water. In its application decompression tank can be reservoir tank and water storage tanks which are closed. In the simulation the value of compressibility is very important for the case decompression tank. The method used is the numerical simulations using OpenFOAM software to know the results of observation the value of the pressure, density, and velocity magnitude. Simulations will be performed by varying the value of the water compressibility 4.54e-06 4.54e-07, and 4.54e-08. Before performing simulations on the main case decompression tank then first performed by grid independent test to validate the simulation results from the study by another researcher. From the results of experiments with variation of compressibility of water it can be seen that a good comparisons with numerical simulation and previous studies show the capability of this method. The greater the value compressibility water then the pressure distribution generated more widely and rapidly spreadas well as the velocity distribution. However for the distribution of the speed with greater compressibility of the velocity distribution will become more varied and occurs only in a small area.

Numerical Study on Duct Acoustic Modal and Source Flow Structure of Fan Tones With Leaned and Swept Stator

2020 ◽  
Author(s):  
Wang Liangfeng ◽  
Mao Luqin ◽  
Xiang Kangshen ◽  
Duan Wenhua ◽  
Tong Hang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Noise Reduction ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Sweep Angle ◽  
Lean Angle ◽  
Stator Blade ◽  
Angle Blade ◽  
Simulation Results

Abstract The present study is focused on the fan tone noise reduction with leaned and swept stator blade. A hybrid URANS/Goldstein’s equations method is used to calculate the unsteady flow and tone noise of a high loaded axial-flow fan. The numerical simulation results show that the fan tone noise will be increased with negative angle lean, while it will be reduced with positive lean angle. The higher the harmonic number, the larger the noise reduction with positive lean angle blade. It is found that when the stator blade sweeps back of 30 degrees, the fan tone noise at the fan inlet can be reduced by 5.5 dB, while the fan tone noise at the fan outlet can be reduced by 9.8dB. It is also found that the combined leaned and swept blade has the largest noise reduction. When the fan stator blade lean angle and sweep angle are both 30 degrees, the fan inlet tone noise can be reduced by 8.5 dB, while the fan outlet tone noise can be reduced by 17dB. The numerical simulation results indicate that the influence of blade lean and sweep on fan mass flow is less than 1% within the scope of this study. The negative lean angle of stator blade can improve the aerodynamic performance, but the positive lean angle of the stator blade will reduce the total pressure ratio and isentropic efficiency of the fan.

Growth of Secondary Flow Losses Downstream of a Turbine Blade Cascade

1986 ◽  
Vol 108 (2) ◽  
pp. 270-276 ◽  
Author(s):  
L. D. Chen ◽  
S. L. Dixon
Keyword(s):  
Boundary Layer ◽  
Aspect Ratio ◽  
Secondary Flow ◽  
Total Pressure ◽  
Turbine Cascade ◽  
Pressure Losses ◽  
Flow Losses ◽  
Blade Cascade ◽  
Flow Loss ◽  
Loss Coefficients

Endwall total pressure losses downstream of a low-speed turbine cascade have been measured at several planes in order to determine the changes in secondary flow loss coefficients and the growth of the mixing loss with distance downstream. The results obtained are compared with various published secondary flow loss correlations in an attempt to explain some of the anomalies which presently exist. The paper includes some new correlations including one for the important gross secondary loss coefficient YSG with loading and aspect ratio parameters as well as the upstream boundary layer parameters.

Effect of the Distance between Guided Needle and Cone Body on Properties of Vortex Spun Yarn

2014 ◽  
Vol 1048 ◽  
pp. 575-578
Author(s):  
Mei Ling Li ◽  
Chong Wen Yu ◽  
Shan Shan Shang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Pressure Distribution ◽  
Air Flow ◽  
Yarn Quality ◽  
Spun Yarn ◽  
Simulation Results ◽  
Dynamics Models

Effects of the distance between guided needle and cone body on properties of MVS yarns were investigated by numerical simulation. 5 groups of the distance are designed (0.5mm, 1mm, 1.5mm, 2mm and 2.5mm). The 3D computational fluid dynamics models are established to conduct the numerical simulation of the airflow in the nozzle. Through analysis of the characteristics of air flow inside the different nozzles, such as pressure distribution and velocity vectors, the motion of drafted fibers and performances of yarns are discussed. Simulation results show that when the distance is 1.5mm, the airflow state within the nozzle is beneficial to form more open-ends and twist, and the yarn quality would be better.

Aero-Thermal Performance of a Rotor Blade Cascade With Stator-Rotor Seal Purge Flow

2012 ◽  
Author(s):  
G. Barigozzi ◽  
F. Fontaneto ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
M. Maritano ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Thermal Performance ◽  
Flow Injection ◽  
Rotor Blade ◽  
Thermal Protection ◽  
Leading Edge ◽  
Pressure Probe ◽  
Blade Cascade ◽  
Purge Flow ◽  
End Wall

The present paper investigates the effects of purge flow from a stator-rotor seal gap on the aerodynamic and thermal performance of a rotor blade cascade. Particular attention is paid to thermal results in the leading edge area that is typically difficult to protect. Experimental tests have been performed on a seven-blade cascade of a high-pressure rotor stage of a real gas turbine at low Mach number (Ma2is = 0.3). To simulate the rotational effect in a linear cascade environment, a number of inclined fins have been installed inside the stator-rotor gap, making the coolant flow to exit with the right tangential velocity component. Tests have been carried out at different blowing conditions, with mass flow rate ratios up to 2.0%. Aerodynamic effects of purge flow on secondary flow structures were surveyed by traversing a 5-hole miniaturized pressure probe in a plane 0.08cax downstream of the trailing edge. Film cooling effectiveness distributions on the end wall platform were obtained by using Thermochromic Liquid Crystals technique. Results allowed to investigate the effect of purge flow injection from the upstream gap on the secondary flows development and on the thermal protection capability. Purge flow injection of 1.0% reduced secondary flow losses and was found to effectively protect the front end wall region, up to about 0.5cax downstream of the leading edge. Increasing the purge flow up to 1.5%–2.0% provided a better thermal protection not only stream wise, but also in the region close to the leading edge because of the weakened washing activity of the horseshoe vortex.

Investigation on the Effect of Streamwise Grooves on Controlling Corner Flow Separation

2016 ◽  
Author(s):  
Weilin Yi ◽  
Jiabin Li ◽  
Jia Yu ◽  
Lucheng Ji
Keyword(s):  
Secondary Flow ◽  
Flow Separation ◽  
Flow Analysis ◽  
Suction Side ◽  
Numerical Comparison ◽  
Linear Diffusion ◽  
Turning Angle ◽  
Corner Flow ◽  
Flow Loss ◽  
End Wall

Flow separations often take place in the junction of blades and endwalls and limit seriously the aerodynamic loading increase of turbomachinery, which are caused mainly by mixing of the boundary layers on blades and endwall surfaces and the transverse secondary flow generated by the pressure difference between the pressure and suction side. Firstly, focusing on a linear diffusion cascade with 42 degrees turning angle, it can be found that the transverse secondary flow can be reduced by inviscid hub and the flow separation is eliminated further through the numerical comparison between the viscous and inviscid hub cases. So the transverse secondary flow is the dominate factor for the flow separation in this cascade. We should try to control the transverse secondary flow to reduce the flow separation. Secondly, based above analysis, the flow separation can be controlled effectively if we can cut off the secondary flow. So nine kinds of streamwise groove schemes are designed and analyzed. It can be seen that the streamwise grooves at the end wall inhibit obviously the transverse secondary flow but the flow structure change is different at different span. There is an optimum combination of width and height of groove, and the height is more important than width. Thirdly, the detailed flow analysis of best scheme with smaller width, moderate height are carried out. It can decrease the separation zone scope at the corner zone, reduce the energy loss coefficient and also reduce the flow loss.

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