Numerical simulation of tip leakage vortex effect on hydrogen-combustion flow around 3D turbine blade

An experimental investigation concerning tip flow field unsteadiness was performed for a high-performance, state-of-the-art transonic compressor rotor. Casing-mounted high frequency response pressure transducers were used to indicate both the ensemble averaged and time varying flow structure present in the tip region of the rotor at four different operating points at design speed. The ensemble averaged information revealed the shock structure as it evolved from a dual shock system at open throttle to an attached shock at peak efficiency to a detached orientation at near stall. Steady three-dimensional Navier Stokes analysis reveals the dominant flow structures in the tip region in support of the ensemble averaged measurements. A tip leakage vortex is evident at all operating points as regions of low static pressure and appears in the same location as the vortex found in the numerical solution. An unsteadiness parameter was calculated to quantify the unsteadiness in the tip cascade plane. In general, regions of peak unsteadiness appear near shocks and in the area interpreted as the shock-tip leakage vortex interaction. Local peaks of unsteadiness appear in mid-passage downstream of the shock-vortex interaction. Flow field features not evident in the ensemble averaged data are examined via a Navier-Stokes solution obtained at the near stall operating point.

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Unsteady Aperiodic Behavior of a Periodically Disturbed Tip-Leakage Vortex

AIAA Journal ◽

10.2514/1.13539 ◽

2008 ◽

Vol 46 (5) ◽

pp. 1025-1038 ◽

Cited By ~ 1

Author(s):

Ruolong Ma ◽

William J. Devenport

Keyword(s):

Tip Leakage Vortex ◽

Tip Leakage

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Measurements of the Tip Clearance Flow for a High-Reynolds-Number Axial-Flow Rotor

Journal of Turbomachinery ◽

10.1115/1.2836564 ◽

1995 ◽

Vol 117 (4) ◽

pp. 522-532 ◽

Cited By ~ 23

Author(s):

W. C. Zierke ◽

K. J. Farrell ◽

W. A. Straka

Keyword(s):

Reynolds Number ◽

Flow Visualization ◽

Vortex Core ◽

Rotor Blade ◽

High Reynolds Number ◽

Tip Clearance ◽

Tip Leakage Vortex ◽

Tip Leakage ◽

Blade Tip ◽

High Reynolds

A high-Reynolds-number pump (HIREP) facility has been used to acquire flow measurements in the rotor blade tip clearance region, with blade chord Reynolds numbers of 3,900,000 and 5,500,000. The initial experiment involved rotor blades with varying tip clearances, while a second experiment involved a more detailed investigation of a rotor blade row with a single tip clearance. The flow visualization on the blade surface and within the flow field indicate the existence of a trailing-edge separation vortex, a vortex that migrates radially upward along the trailing edge and then turns in the circumferential direction near the casing, moving in the opposite direction of blade rotation. Flow visualization also helps in establishing the trajectory of the tip leakage vortex core and shows the unsteadiness of the vortex. Detailed measurements show the effects of tip clearance size and downstream distance on the structure of the rotor tip leakage vortex. The character of the velocity profile along the vortex core changes from a jetlike profile to a wakelike profile as the tip clearance becomes smaller. Also, for small clearances, the presence and proximity of the casing endwall affects the roll-up, shape, dissipation, and unsteadiness of the tip leakage vortex. Measurements also show how much circulation is retained by the blade tip and how much is shed into the vortex, a vortex associated with high losses.

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Numerical Simulation of Impinging Cooling on the Leading Edge of a Turbine Blade

Volume 10: Heat and Mass Transport Processes, Parts A and B ◽

10.1115/imece2011-63649 ◽

2011 ◽

Author(s):

Keyong Cheng ◽

Xiulan Huai ◽

Jun Cai ◽

Zhixiong Guo

Keyword(s):

Numerical Simulation ◽

Turbine Blade ◽

Leading Edge ◽

Critical Factor ◽

Main Stream ◽

Experimental Conditions ◽

Cooling Effectiveness ◽

Blowing Ratio ◽

Lower Temperature ◽

Simulation Parameters

In the present study, numerical simulation is carried out for impingement/effusion cooling on the leading edge of a turbine blade similar to an experimental model tested previously. The k-ε turbulence model is used, and simulation parameters are set in accordance with the experimental conditions, including temperature ratio, blowing ratio, and Reynolds number of the main stream. The accuracy and reliability of the simulation is verified by the experimental data, and the influence of various factors on fluid flow and heat transfer is analyzed in detail. The results indicate that the blowing ratio is one critical factor which affects the cooling effectiveness. The greater the blowing ratio is, the higher the cooling effectiveness is. In addition, a staggered-holes arrangement is numerically studied and compared with a line-holes arrangement. The results show that the staggered-holes arrangement has a lower temperature on the outer surface of the leading edge and has improved the cooling effectiveness.

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The Behavior of the Casing Boundary Layer With the Presence of Tip Leakage Vortex

Volume 2A: Turbomachinery ◽

10.1115/gt2018-75916 ◽

2018 ◽

Cited By ~ 2

Author(s):

Xi Nan ◽

Feng Lin ◽

Takehiro Himeno ◽

Toshinori Watanabe

Keyword(s):

Boundary Layer ◽

Skin Friction ◽

Three Dimensional ◽

Pressure Rise ◽

Rotating Stall ◽

Tip Leakage Vortex ◽

Tip Leakage ◽

Transonic Compressor ◽

Flow Loss ◽

Produce Flow

Casing boundary layer effectively places a limit on the pressure rise capability achievable by the compressor. The separation of the casing boundary layer not only produce flow loss but also closely related to the compressor rotating stall. The motivation of this paper is to present a viewpoint that the casing boundary layer should be paid attention to in parallel with other flow factors on rotating stall trigger. This paper illustrates the casing boundary layer behavior by displaying its separation phenomena with the presence of tip leakage vortex at different flow conditions. Skin friction lines and the corresponding absolute streamlines are used to demonstrate the three-dimensional flow patterns on and near the casing. The results depict a Saddle, a Node and several tufts of skin friction lines dividing the passage into four zones. The tip leakage vortex is enfolded within one of the zones by the separated flows. All the flows in each blade passage are confined within the passage as long as the compressor is stable. The casing boundary layer of a transonic compressor is also examined in the same way, which results in qualitatively similar zonal flows that enfolds the tip leakage vortex. This research develops a new way to study the casing boundary layer in rotating compressors. The results may provide a first-principle based explanation to stalling mechanisms for compressors that are casing sensitive.

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Unsteady Tip Leakage Vortex Cavitation Originating From the Tip Clearance of an Oscillating Hydrofoil

Journal of Fluids Engineering ◽

10.1115/1.2173290 ◽

2005 ◽

Vol 128 (3) ◽

pp. 421-429 ◽

Cited By ~ 22

Author(s):

Masahiro Murayama ◽

Yoshiki Yoshida ◽

Yoshinobu Tsujimoto

Keyword(s):

Steady State ◽

Qualitative Agreement ◽

Cavity Growth ◽

Simple Calculation ◽

Tip Clearance ◽

Cavity Volume ◽

Cavity Size ◽

Tip Leakage Vortex ◽

Tip Leakage ◽

Unsteady Characteristics

Tip leakage vortex cavitations originating from the tip clearance of an oscillating hydrofoil were observed experimentally. It was found that the delay between the unsteady and the steady-state results of the tip leakage vortex cavitation increase, and that the maximum cavity size decreases when the reduced oscillating frequency increases. To simulate the unsteady characteristics of tip leakage vortex cavitation, a simple calculation based on slender body approximation was conducted taking into account the effect of cavity growth. The calculation and experimental results of the cavity volume fluctuation were found to be in qualitative agreement.

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Numerical Simulation of Methane-Hydrogen Combustion in the Air: Influence on Combustion Parameters

Indian Journal of Science and Technology ◽

10.17485/ijst/2018/v11i2/120608 ◽

2018 ◽

Vol 11 (2) ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Mohammed El Hadi Attia ◽

Abderrahmane Khechekhouche ◽

Zied Driss ◽

◽

...

Keyword(s):

Numerical Simulation ◽

Hydrogen Combustion

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Numerical and Experimental Investigation of Tip Leakage Vortex Trajectory in an Axial Flow Pump

Volume 1B, Symposia: Fluid Machinery; Fluid Power; Fluid-Structure Interaction and Flow-Induced Noise in Industrial Applications; Flow Applications in Aerospace; Flow Manipulation and Active Control: Theory, Experiments and Implementation; Fundamental Issues and Perspectives in Fluid Mechanics ◽

10.1115/fedsm2013-16058 ◽

2013 ◽

Author(s):

Desheng Zhang ◽

Weidong Shi ◽

Suqing Wu ◽

Dazhi Pan ◽

Peipei Shao ◽

...

Keyword(s):

Flow Rate ◽

Axial Flow ◽

Tip Clearance ◽

High Speed Photography ◽

Rate Condition ◽

Tip Leakage Vortex ◽

Tip Leakage ◽

Starting Point ◽

Axial Flow Pump ◽

Flow Pump

In this paper, the tip leakage vortex (TLV) structures in an axial flow pump were investigated by numerical and experimental methods. Based on the comparisons of different blade tip clearance size (i.e., 0.5 mm, 1mm and 1.5mm) and different flow rate conditions, TLV trajectories were obtained by Swirling Strength method, and simulated by modified SST k-ω turbulence model with refined high-quality structured grids. A high-speed photography test was carried out to capture the tip leakage vortex cavitation in an axial flow pump with transparent casing. Numerical results were compared with the experimental leakage vortex trajectories, and a good agreement is presented. The detailed trajectories show that the start point of tip leakage vortex appears near the leading edge at small flow rate, and it moves from trailing edge to about 30% chord span at rated flow rate. At the larger flow rate condition, the starting point of TLV shifts to the middle of chord, and the direction of TLV moves parallel to the blade hydrofoil. As the increasing of the tip size, the start point of TLV trajectories moves to the central of chord and the minimum pressure in vortex core is gradually reduced.

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