Three-Dimensional Aerodynamic Characteristics of Fan Rotor with Large Bypass Ratio in Distorted Flow Field

For the problem of one time trajectory correction, a new correction mechanism changing the resistance pieces area is given. The projectile motion locus can be controlled by increasing resistance. In view of the issue of correction trajectory of flying body, the aerodynamic characteristics are changed by the size of resistance ring unfolded area. The comparison between resistance ring flying body and ordinary flying body has been analyzed about the three-dimensional flow field in different sonic. This paper researches related variation and factors of the aerodynamic characteristics with the size of resistance ring unfolded area as a characteristic parameter. The changes of the size of resistance ring unfolded area have a significant impact on resistance coefficient of the flying body. Damping plate affects the part flow field of the flying body and then the whole flow field. On the leeward side of damping plate, there forms the obvious whirlpool area. Due to the low pressure of the whirlpool area, there brings the pressure difference between windward and leeward of the damping plate, and this situation exists in the conditions of subsonic, transonic, and supersonic.

Download Full-text

NUMERICAL INVESTIGATION OF A TONE NOISE OF THE FAN WITH CASING TREATMENT

Perm National Research Polytechnic University Aerospace Engineering Bulletin ◽

10.15593/2224-9982/2021.66.03 ◽

2021 ◽

pp. 24-38

Author(s):

Yaroslav Druzhinin ◽

◽

Viktor Mileshin ◽

Anton Rossikhin ◽

◽

...

Keyword(s):

Flow Field ◽

Unsteady Flow ◽

Numerical Investigation ◽

Significant Influence ◽

Aerodynamic Characteristics ◽

Operational Conditions ◽

Casing Treatment ◽

Harmonic Method ◽

Surge Line ◽

Bypass Ratio

Numerical investigation of influence of a slot-type casing treatment on acoustic and aerodynamic characteristics of the fan of ultra-high bypass ratio turbofan is presented. The investigation was performed using NUMECA FINE/Turbo solver. NLH harmonic method was used to simulate the effect of casing treatment on unsteady flow field in the turbomachine. Two operational conditions were investigated – “sideline” and “approach”. The attention for the first operational condition was paid for aerodynamic characteristics. Significant influence of casing treatment on them was found especially near the surge line. At the “approach” operational conditions the attention was paid for the proper calculation of tone noise. It was shown that the installation of casing treatment leads to decrease of power of tone noise radiated through the inlet. However the power of the tone noise, radiated through the nozzle, and also the overall power of tone noise increase.

Download Full-text

Unsteady Aerodynamic Characteristics of a High Speed Train with Crosswind

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.1878 ◽

2011 ◽

Vol 66-68 ◽

pp. 1878-1882

Author(s):

Ming Lu Zhang ◽

Yi Ren Yang ◽

Chen Guang Fan ◽

Li Lu

Keyword(s):

Wind Tunnel ◽

Flow Field ◽

High Speed ◽

Stokes Equations ◽

Three Dimensional ◽

Aerodynamic Characteristics ◽

Navier Stokes ◽

Vehicle Speed ◽

High Speed Train ◽

Mesh Method

The aerodynamic performances of a high speed train will significant change under the action of the crosswind. Large eddy simulation (LES) was made to solve the flow around a simplified CRH2 high speed train with 250km/h and 350km/h under the influence of a crosswind with 28.4m/s base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of static train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field around train is completely different between Wind tunnel experiment and factual running. Many vortices will be produced on the leeside of the train with alternately vehicle bottom and back under the influence of a crosswind. The flow field around train is similar with different vehicle speed.

Download Full-text

Simulation of Interference Characteristics of the Model Supporting Beams with Different Forms of Section in Wind Tunnel Test

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1025-1026.910 ◽

2014 ◽

Vol 1025-1026 ◽

pp. 910-913

Author(s):

Xing Jun Hu ◽

Yue Xing Miao

Keyword(s):

Wind Tunnel ◽

Flow Field ◽

Three Dimensional ◽

Wind Tunnel Test ◽

Aerodynamic Characteristics ◽

Three Dimensional Flow ◽

Ansys Fluent ◽

Correction Error ◽

Dimensional Flow ◽

Pressure Distributions

In order to study the effects of the supporting beams with different forms of section on the aerodynamic characteristics of car models. Model supporting beams with three different forms of section were designed based on standard MIRA model. The commercial CFD software - Ansys Fluent was used to simulate the three-dimensional flow field around the standard MIRA model installed with three different kinds of supporting beams. With comparisons between the drag coefficients, pressure distributions and velocity distributions around the wheels with the different supporting beams, the reasons for the differences in aerodynamics are analyzed and advices were given for helping choosing the supporting beam with minimal disturbance to reduce the correction error.

Download Full-text

Numerical Investigation of Internal Flow Field for Modified Design of Eckardt Backswept Impeller

Volume 1: Turbomachinery ◽

10.1115/98-gt-296 ◽

1998 ◽

Cited By ~ 1

Author(s):

JongSik Oh

Keyword(s):

Flow Field ◽

Static Pressure ◽

Pressure Ratio ◽

Three Dimensional ◽

Internal Flow ◽

Aerodynamic Characteristics ◽

Uniform Flow ◽

Spanwise Direction ◽

Vaneless Diffuser ◽

Blade Thickness

The three dimensional blade shape of Eckardt’s backswept impeller was modified, expecting better aerodynamic performance of the internal flow field. Blade angle distributions and parts of the meridional contours were changed, while impeller diameter, blade number, blade thickness and blade inlet and exit angles remained unchanged. The casing contour in the vaneless diffuser is additionally changed in a smooth manner to obtain 15% pinched flow channel at the exit. With the help of the three dimensional compressible Navier-Stokes analysis method, some improvements in the aerodynamic characteristics of the internal flow field were found; a more uniform flow field in the circumferential direction at impeller discharge was established, and a more favorable rise of static pressure near the casing in the impeller passage was made. A more effective increase of static pressure in the vaneless diffuser was also found. But a less uniform flow field in the spanwise direction at impeller exit resulted. The same levels of total-to-total pressure ratio and isentropic efficiency of the compressor were obtained, while an increase of choking flow rate was obtained due to increased throat area.

Download Full-text