Numerical Study on the Variation of Axial Thrust of Rotating Disc with Pump-Out Vane

This paper presents a numerical study of the effect of rotor mounted bolts on the moment coefficient and flow structure within a rotor-stator cavity representative of modern gas turbine engine design. The CFD computations are performed using the commercial code FLUENT. The simulation methodology is first validated using experimental data from plain co-rotating disc and rotor-stator cavities from the open literature. Comparisons are then made with experimental data obtained from a test rig at the Thermo Fluid Mechanics Research Centre (TFMRC), University of Sussex. Computations were performed at Reφ = 6.8 × 106, Cw = 5929 (λT = 0.35) with different numbers of bolts (0 < N < 60), and also a continuous ring, at r/b = 0.9. The study has improved the current understanding of the effect on moment coefficient and flow structure that rotor mounted protrusions have in rotor-stator systems. It is seen that the contribution of skin friction to the moment coefficient reduces as the number of bolts is increased. The size and shape of the wake created by a rotating bolt also means that the pressure loss per bolt reduces with N but the overall effect is to increase the moment coefficient because there are more bolts.

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Investigation on Aeroacoustics and Aerodynamics of the Stator Lean Effect for Rotor-Stator Interaction

Volume 6C: Turbomachinery ◽

10.1115/gt2013-94554 ◽

2013 ◽

Author(s):

Hai-jian Liu ◽

Hua Ouyang ◽

Ya-dong Wu ◽

Jie Tian ◽

Zhao-hui Du

Keyword(s):

Numerical Study ◽

Leading Edge ◽

Phase Lag ◽

Axial Thrust ◽

Unsteady Force ◽

Lean Angle ◽

Rotor Stator Interaction ◽

Stator Blade ◽

Unsteady Loading ◽

Thrust And Torque

The rotor-stator interaction in a 1.5 stage compressor with different lean angle of downstream stator blades was investigated by aeroacoustic and numerical study. The aeroacoustic performance with narrow spectra, the sound pressure level distribution and the unsteady loading of the compressor were tested and analyzed. The RMS pressure, the axial thrust and torque of the downstream stator blade distribution revealed the unsteady characteristic of rotor-stator interaction at different downstream stator blade lean angle. The positive lean stator had better noise constraint than the negative lean stator. However, the RMS pressure and the unsteady force increased with the increase of the lean angle when the stator had positive lean angle. The time-spatial contours of the axial velocity demonstrated the effect of time delay for the rotor wake intersection with the leading edge of the stator blade. And the phase lag distribution of the wake presented the detail distribution of the wake phase along the span. The downstream stator blade lean was effective to obtain a significant reduction for the unsteady force and get large phase lag for the rotor’s wake of rotor-stator interaction. Leaned positive blade had better benefits than negative for the noise reduction and the phase lag of the wake.

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Influence of Peripheral Opening on the Central Core Flow Behaviour in a Rotor-Stator System

Volume 1: Symposia, Parts A, B and C ◽

10.1115/fedsm2009-78088 ◽

2009 ◽

Author(s):

Fadi Abdel Nour ◽

Roger Debuchy ◽

Ge´rard Bois ◽

Hassan Naji

Keyword(s):

Static Pressure ◽

Radial Flow ◽

Numerical Study ◽

Outer Region ◽

Experimental Tests ◽

Flow Property ◽

Computation Method ◽

Swirl Ratio ◽

Rotating Disc ◽

The Core

This work relates to an experimental, theoretical and numerical study of a turbulent flow with separated boundary layers between a rotating disc (rotor) and a stationary one (stator) without any superposed radial flow. The originality of this study is that the pre-swirl ratio at the periphery of the cavity (Kp) is lower than the core swirl ratio (KB) corresponding to the solid body rotation, as predicted by Batchelor in the case of infinite discs: this is what the authors call a rotor-stator system with low pre-swirl ratio. Under these conditions, recent works have shown that the core swirl ratio (K) is a decreasing function of the radius, at least in the peripheral region. This behaviour has rather been observed in the cavities with superposed centripetal radial flow. In the present paper, this flow property is explained starting from an asymptotic approach which leads to step-by-step analytical computation method of the radial distribution of the core swirl ratio (K) and of the static pressure on the stator side p*. The validation of the theory is based both on experimental and numerical results. The experimental tests are carried out in a rotor-stator cavity for different values of the pre-swirl ratio, which is done by geometrical changes of the periphery of the system. The experimental data mostly include the velocity measurements and the turbulent correlations by hot-wire anemometry in interstice between the discs, as well as the static pressure measurements on the stator side. Comparisons with predictions from the CFD code Fluent are also provided. The numerical simulations are performed using the two-equation k – ω SST turbulence model, assuming a 2D-axisymmetric steady flow, in a domain corresponding to the inter-disks spacing and the peripheral outer region of the cavity. Computed and experimental values are in good agreement with the theoretical results.

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Numerical Study on the Effect of Cavity Vanes to Control the Axial Thrust of a Turbopump

Journal of Fluid Machinery ◽

10.5293/kfma.2006.9.2.039 ◽

2006 ◽

Vol 9 (2) ◽

pp. 39-43 ◽

Cited By ~ 1

Keyword(s):

Numerical Study ◽

Axial Thrust

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Numerical Study of Internal Flow Fields in Steam Turbine Stages With Balance Holes

Volume 7: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2010-23704 ◽

2010 ◽

Author(s):

Chang Luo ◽

Liming Song ◽

Jun Li ◽

Zhenping Feng ◽

Shouhong Cao ◽

...

Keyword(s):

Steam Turbine ◽

Numerical Study ◽

Flow Characteristics ◽

Internal Flow ◽

Aerodynamic Performance ◽

Flow Path ◽

Total Efficiency ◽

Axial Thrust ◽

Ideal Flow ◽

The Impact

A new calculation model is proposed to simulate flows in the steam turbine stages with balance holes in this paper. The model describes the flows in a 2.5 stage turbine with focus on the second stage and the corresponding seals, balance holes and disk cavities. The aerodynamic performance of the turbine stages is predicted by using a three-dimensional Reynold-Averaged Navier-Stokes (RANS) solver. The Spalart-Allmaras one equation turbulence model is adopted, and the RANS solver is run in steady mode using the mixing plane approach. In order to analyze the impact of leakage flow on main flow, the aerodynamic performance of the ideal flow path turbine stages (without balance holes and seals) is also calculated. The numerical results show that the total-total efficiency of the turbine stages with balance holes is 1.81% lower than that of ideal flow path turbine stages. The flow characteristics in the seals, disk cavities and balance holes and their influence on the mainstream are described. Finally, the influence of the balance hole diameter and radius crossing the balance hole axis on the turbine stage performance is studied. The variations of the torque, axial thrust and relative efficiency with the diameter and radius are presented respectively.

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Effect of Surface Roughness on Aerodynamic Performance of Turbine Rear Structure

Volume 1: Aircraft Engine; Fans and Blowers; Marine; Honors and Awards ◽

10.1115/gt2019-90472 ◽

2019 ◽

Author(s):

Srikanth Deshpande ◽

Isak Jonsson ◽

Valery Chernoray

Keyword(s):

Boundary Layer ◽

Surface Roughness ◽

Reynolds Number ◽

Numerical Analysis ◽

Numerical Simulations ◽

Numerical Study ◽

Aerodynamic Performance ◽

Axial Thrust ◽

Low Pressure Turbine ◽

Effect Of Surface

Abstract A turbine rear structure (TRS) is typically used to deswirl the flow from the low pressure turbine (LPT) and hence maximize the axial thrust. It is important to study the effect of surface roughness on aerodynamic performance of TRS. Numerical simulations with surface roughness are performed and results are compared with the data from experiments. Comparisons show that the trends between the numerical analysis and the experiments are in line with one another. Further understanding of numerical analysis shows that, at higher Reynolds number, the effect of surface roughness is more significant when compared to the effects at low-Reynolds number. An attempt has been made to study the transition behavior in the presence of surface roughness. Since boundary layer measurements are planned for the rig, this numerical study provides good inputs in order to plan instrumentation.

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Global stability of the rotating-disc boundary layer with an axial magnetic field

Journal of Fluid Mechanics ◽

10.1017/jfm.2013.162 ◽

2013 ◽

Vol 724 ◽

pp. 510-526 ◽

Cited By ~ 11

Author(s):

Christian Thomas ◽

Christopher Davies

Keyword(s):

Magnetic Field ◽

Boundary Layer ◽

Linear Stability ◽

Axial Magnetic Field ◽

Numerical Study ◽

Control Strategies ◽

Base Flow ◽

Global Instability ◽

Rotating Disc ◽

Radially Inhomogeneous

AbstractA numerical study is conducted to investigate the influence of a uniform axial magnetic field on the global linear stability of the rotating-disc boundary layer. Simulation results obtained using a radially homogenized base flow were found to be in excellent agreement with an earlier linear stability analysis, which indicated that an axial magnetic field can locally suppress both convective and absolute instabilities. However, the numerical results obtained for the genuine, radially inhomogeneous, flow indicate that a global form of instability develops for sufficiently large magnetic fields. The qualitative nature of the global instability is similar to that which was observed in a previous study, where mass suction was applied at the rotating disc surface. It is shown that, just as for the case with mass suction, it is possible to explain the promotion of global instability by considering a model that includes detuning effects, which are associated with the radial variation of locally defined absolute temporal frequencies. The recurrence of the same type of instability behaviour when two distinct flow control strategies are implemented, one using suction and the other an axial magnetic field, indicates that the phenomena described by the model may be considered generic.

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