Successes and Challenges for Flow Control Simulations (Invited)

Rumsey, Christopher L.

doi:10.2514/6.2008-4311

Cited by 31 publications

(19 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rumsey et al emphasized that there were differences between particle image velocimetry (PIV) and laser Doppler velocimetry (LDV) measurements of the current case in some regions of the flow, and the URANS computations tended to agree better with the LDV data in those regions. In confirmation, all turbulence models by the coarse grid of Rumsey in a normal domain size can capture the general character of the flow. Dandois et al computed the current test case and used both URANS (with Spalart–Allmaras) and large‐eddy simulation (LES) (with a selective mixed‐scale subgrid scale model).…”

Section: Introductionmentioning

confidence: 69%

“…Although the three investigated turbulence models produced some differences, these differences were generally not too large. Rumsey reported that unsteady RANS (URANS) was particularly unsuccessful to predict turbulence quantities. Rumsey et al emphasized that there were differences between particle image velocimetry (PIV) and laser Doppler velocimetry (LDV) measurements of the current case in some regions of the flow, and the URANS computations tended to agree better with the LDV data in those regions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical prediction of turbulent flow structure generated by a synthetic cross‐jet into a turbulent boundary layer

Javadi

El‐Askary

2011

Numerical Methods in Fluids

View full text Add to dashboard Cite

SUMMARY A detailed numerical study using large‐eddy simulation (LES) and unsteady Reynolds‐averaged Navier–Stokes (URANS) was undertaken to investigate physical processes that are engendered in the injection of a circular synthetic (zero‐net mass flux) jet in a zero pressure gradient turbulent boundary layer. A complementary study was carried out and was verified by comparisons with the available experimental data that were obtained at corresponding conditions with the aim of achieving an improved understanding of fluid dynamics of the studied processes. The computations were conducted by OpenFOAM C++, and the physical realism of the incoming turbulent boundary layer was secured by employing random field generation algorithm. The cavity was computed with a sinusoidal transpiration boundary condition on its floor. The results from URANS computation and LES were compared and described qualitatively and quantitatively. There is a particular interest for acquiring the turbulent structures from the present numerical data. The numerical methods can capture vortical structures including a hairpin (primary) vortex and secondary structures. However, the present computations confirmed that URANS and LES are capable of predicting current flow field with a more detailed structure presented by LES data as expected. Copyright © 2011 John Wiley & Sons, Ltd.

show abstract

Section: Introductionmentioning

confidence: 69%

Section: Introductionmentioning

confidence: 99%

Numerical prediction of turbulent flow structure generated by a synthetic cross‐jet into a turbulent boundary layer

Javadi

El‐Askary

2011

Numerical Methods in Fluids

View full text Add to dashboard Cite

show abstract

“…The model of the plenum follows one described by Rumsey et al . and Iaccarino et al . The trailing edge of the grid with the plenum is shown in Figure .…”

Section: Methodsmentioning

confidence: 92%

Comparison of pneumatic jets and tabs for Active Aerodynamic Load Control

Blaylock¹,

Chow²,

Cooperman³

et al. 2013

Wind Energy

View full text Add to dashboard Cite

A fast, efficient way to control loads on utility scale wind turbines is important for the growth of the wind industry. Microtabs and microjets are two Active Aerodynamic Load Control devices, which address this need. Both act perpendicular to the surface of the airfoil, and these actively controlled devices are used to mitigate changes in aerodynamic loading experienced by wind turbine rotors due to wind gusts, wind shear, or other atmospheric phenomena. This work explores the aerodynamic effects of microjets and then compares them to those of microtabs. Flow around an airfoil with an activated microjet at the trailing edge has been simulated using the Reynolds-averaged Navier-Stokes solver OVERFLOW-2. Using a Chimera overset grid topology, a microjet has been placed near the trailing edge of the lower surface of a NACA 0012 airfoil. For a jet velocity about half of the freestream velocity, the microjet can change the lift up to ΔC L = 0.2, but the amount of change varies with the momentum coefficient of the jet. The change in lift is not symmetric for positive and negative angles of attack due to changes in the boundary layer thickness with angle of attack. Increasing the Reynolds number reduces the effectiveness of the microjet only slightly. The effects of jet velocity, jet activation time, and airfoil angle of attack on airfoil lift, drag, and pitching moment are compared with previous work, which illustrates the deployment of a microtab at the 95% chord location of a NACA 0012 airfoil. This study shows that microjets and microtabs have very similar responses in lift and pitching moment, but the drag for the microjet is noticeably lower.

show abstract

“…Tang and Zhong [17] pointed out that results from the numerical simulation of traditional blowing synthetic jet with the standard k- turbulent model were the closest to the experimental results. Zhang and Wang [18] also used the standard k- turbulent model to simulate the synthetic jet in a quiescent environment, and the results matched quite well with the benchmark experimental data of NASA Langley Research Center [19]. The details of the governing equations and numerical method can be found in the author's previous work [13].…”

Section: Governing Equations and Numerical Methodsmentioning

confidence: 58%

The effect of actuation frequency on the plasma synthetic jet

Zhang

Dai

Liu

et al. 2011

Sci. China Technol. Sci.

View full text Add to dashboard Cite

The flow induced by plasma synthetic jet actuator was simulated through solving the Reynolds-averaged Navier-Stokes equations augmented by body force phenomenological plasma model. The effect of actuation frequency on the plasma synthetic jet was examined by case study. The numerical results present that with the actuation frequency increasing, the stream-wise distance of the adjacent vortex pairs induced by the actuator decreases monotonically, which is the same as the situation of the velocity fluctuations field caused by the vortex pairs. When the actuation frequency is 60 Hz, the vortex pairs formed during the adjacent actuation periods merge together quickly, and the flow structure in the downstream region is more close to that of the steady case. The actuation frequency has no visible influence on the time-averaged flow field of plasma synthetic jet. However, when the actuation frequency is relatively low (f<40 Hz), the momentum flux close to the actuator increases with the actuation frequency increasing, which is contrary to the situation in the far field from the wall. plasma actuator, synthetic jet, numerical simulation, actuation frequency Citation: Zhang P F, Dai C F, Liu A B, et al. The effect of actuation frequency on the plasma synthetic jet.

show abstract

Successes and Challenges for Flow Control Simulations (Invited)

Cited by 31 publications

References 37 publications

Numerical prediction of turbulent flow structure generated by a synthetic cross‐jet into a turbulent boundary layer

Numerical prediction of turbulent flow structure generated by a synthetic cross‐jet into a turbulent boundary layer

Comparison of pneumatic jets and tabs for Active Aerodynamic Load Control

The effect of actuation frequency on the plasma synthetic jet

Contact Info

Product

Resources

About