Simulations of Turbulent Flow Over Complex Terrain Using an Immersed-Boundary Method

DeLeon, Rey; Sandusky, Micah; Şenocak, İnanç

doi:10.1007/s10546-018-0336-8

Cited by 16 publications

(19 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lundquist et al [9,186] implemented the immersed boundary method in the WRF model and used the method to simulate flows over urban and mountainous terrain. Flow over Bolund hill, the site of a field and model intercomparison study [187,188], has been used to validate implementations of a IBM in several different numerical models [189][190][191][192].…”

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

“…Later methods for combining IBM with a stress boundary condition extended the method to three dimensions, accommodating complex terrain. Several different implementations of IBM with a shear-stress boundary condition have been developed and validated using observations from the Askervein or Bolund hill field experiments [189][190][191][192]194]. These simulations, however, were conducted at the microscale using horizontal resolutions ranging from 1 to 5 m, rather than within the gray zone.…”

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

“…These simulations, however, were conducted at the microscale using horizontal resolutions ranging from 1 to 5 m, rather than within the gray zone. DeLeon et al [192] simulated flow over Askervein hill at slightly coarser horizontal resolutions, ranging from approximately 12 to 25 m. Comparisons with observations were noticeably degraded on the coarse mesh. Bao et al [195] implemented multiple IBM methods into the WRF model and found degraded performance across implementations for flow in an idealized valley using a horizontal resolution of 90 m, indicating that development of an IBM method for the gray zone is still an open area of research.…”

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Crossing Multiple Gray Zones in the Transition from Mesoscale to Microscale Simulation over Complex Terrain

et al. 2019

View full text Add to dashboard Cite

This review paper explores the field of mesoscale to microscale modeling over complex terrain as it traverses multiple so-called gray zones. In an attempt to bridge the gap between previous large-scale and small-scale modeling efforts, atmospheric simulations are being run at an unprecedented range of resolutions. The gray zone is the range of grid resolutions where particular features are neither subgrid nor fully resolved, but rather are partially resolved. The definition of a gray zone depends strongly on the feature being represented and its relationship to the model resolution. This paper explores three gray zones relevant to simulations over complex terrain: turbulence, convection, and topography. Taken together, these may be referred to as the gray continuum. The focus is on horizontal grid resolutions from ∼10 km to ∼10 m. In each case, the challenges are presented together with recent progress in the literature. A common theme is to address cross-scale interaction and scale-awareness in parameterization schemes. How numerical models are designed to cross these gray zones is critical to complex terrain applications in numerical weather prediction, wind resource forecasting, and regional climate modeling, among others.

show abstract

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

Section: Immersed and Embedded Boundary Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Crossing Multiple Gray Zones in the Transition from Mesoscale to Microscale Simulation over Complex Terrain

et al. 2019

View full text Add to dashboard Cite

show abstract

“…IB methods have recently been used to study environmental flows (Tseng and Ferziger 2003;Senocak et al 2004;Chester et al 2007;Jafari et al 2011;Lundquist et al 2010aLundquist et al , 2012Diebold et al 2013;Ma and Liu 2017;DeLeon et al 2018;Bao et al 2016Bao et al , 2018Arthur et al 2018;Wiersema et al 2018Wiersema et al , 2020; however, several of these studies (Tseng and Ferziger 2003;Lundquist et al 2010aLundquist et al , 2012Arthur et al 2018) employed a ghost-cell approach with a no-slip bottom boundary condition for the velocity that has limited applicability to realistic atmospheric boundary layer (ABL) simulations. Due to the presence of unresolved surface roughness elements, ABL simulations typically parameterize the turbulent momentum flux (also known as the turbulent stress) at the surface using Monin-Obukhov similarity theory (MOST; Monin and Obukhov 1954).…”

Section: A Backgroundmentioning

confidence: 99%

Evaluating Implementations of the Immersed Boundary Method in the Weather Research and Forecasting Model

Arthur

Lundquist

Wiersema

et al. 2020

Monthly Weather Review

View full text Add to dashboard Cite

The terrain-following coordinate system used by many atmospheric models can cause numerical instabilities due to discretization errors as resolved terrain slopes increase and the grid becomes highly skewed. The immersed boundary (IB) method, which does not require the grid to conform to the terrain, has been shown to alleviate these errors, and has been used successfully for high-resolution atmospheric simulations over steep terrain, including vertical building surfaces. Since many previous applications of IB methods to atmospheric models have used very fine grid resolution (5 m or less), the present study seeks to evaluate IB method performance over a range of grid resolutions and aspect ratios. Two classes of IB algorithms, velocity reconstruction and shear stress reconstruction, are tested within the common framework of the Weather Research and Forecasting (WRF) Model. Performance is evaluated in two test cases, one with flat terrain and the other with the topography of Askervein Hill, both under neutrally stratified conditions. WRF-IB results are compared to similarity theory, observations, and native WRF results. Despite sensitivity to the location at which the IB intersects the model grid, the velocity reconstruction IB method shows consistent performance when used with a hybrid RANS/LES surface scheme. The shear stress reconstruction IB method is not sensitive to the grid intersection, but is less consistent and near-surface velocity errors can occur at coarse resolutions. This study represents an initial investigation of IB method variability across grid resolutions in WRF. Future work will focus on improving IB method performance at intermediate to coarse resolutions.

show abstract

“…Another article detailing the methods we use to simulate winds over complex terrain and showing some of the associated sensitivities has been submitted for publication [16].…”

Section: Work Publishedmentioning

confidence: 99%

Wind Farm Power Prediction in Complex Terrain

Sandusky¹

Self Cite

View full text Add to dashboard Cite

Simulations of Turbulent Flow Over Complex Terrain Using an Immersed-Boundary Method

Cited by 16 publications

References 53 publications

Crossing Multiple Gray Zones in the Transition from Mesoscale to Microscale Simulation over Complex Terrain

Crossing Multiple Gray Zones in the Transition from Mesoscale to Microscale Simulation over Complex Terrain

Evaluating Implementations of the Immersed Boundary Method in the Weather Research and Forecasting Model

Wind Farm Power Prediction in Complex Terrain

Contact Info

Product

Resources

About