DEKAF: an Open-Source Spectral Boundary-Layer Solver

<p>A set of Python-based tools, WRF4PALM, has been developed for offline-nesting of the PALM model system 6.0 into the Weather Research and Forecasting (WRF) modelling system. Time-dependent boundary conditions of the atmosphere are critical for accurate representation of microscale meteorological dynamics in high resolution real-data simulations. WRF4PALM generates initial and boundary conditions from WRF outputs to provide time-varying meteorological forcing for PALM. The WRF model has been used across the atmospheric science community for a broad range of multidisciplinary applications. The PALM model system 6.0 is a turbulence-resolving large-eddy simulation model with an additional Reynolds averaged Navier&#8211;Stokes (RANS) mode for atmospheric and oceanic boundary layer studies at microscale (Maronga et al., 2020). Currently PALM has the capability to ingest output from the regional scale Consortium for Small-scale Modelling (COSMO) atmospheric prediction model. However, COSMO is not an open source model which requires a licence agreement for operational use or academic research (). This paper describes and validates the new free and open-source WRF4PALM tools (available on ). Two case studies using WRF4PALM are presented for Christchurch, New Zealand, which demonstrate successful PALM simulations driven by meteorological forcing from WRF outputs. The WRF4PALM tools presented here can potentially be used for micro- and mesoscale studies worldwide, for example in boundary layer studies, air pollution dispersion modelling, wildfire emissions and spread, urban weather forecasting, and agricultural meteorology.</p>

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Aerodynamic Design System for Non-Axisymmetric Boundary Layer Ingestion Fans

Volume 2C: Turbomachinery ◽

10.1115/gt2018-77042 ◽

2018 ◽

Author(s):

Sandeep Kumar ◽

Mark G. Turner ◽

Kiran Siddappaji ◽

Mark Celestina

Keyword(s):

Boundary Layer ◽

Open Source ◽

Parametric Design ◽

Leading Edge ◽

Design System ◽

3D Design ◽

Baseline Design ◽

Multiple Process ◽

Turbomachinery Design ◽

Further Development

Non-uniformities at the engine inlet call for novel design techniques to cater to the performance and aeromechanical challenges. The purpose of the fan system is to mitigate the effects of distortion in the flow and to provide thrust to the vehicle. This paper discusses a harmonic based open source design system (NAX) and demonstrates its capabilities for applications in a boundary layer ingesting fan system. First, a primary baseline design was obtained using a typical axisymmetric design approach for the rotor and OGV (Outlet Guide Vanes). This baseline design now serves as the basis for further development, based on user-defined design features. Subsequently, using this baseline design, a circumferentially non-axisymmetric design of the OGV is obtained by means of inducing perturbations in blade leading edge metal angles using Fourier coefficients and phase values. The other parameters that can be varied radially as Bezier curves and tangentially as Fourier modes are: trailing edge metal angle, chord, lean, sweep, curvature and thickness. A smooth spanwise curvature controlled 3D design of OGV is discussed using the open-source geometry generator, T-Blade3. The OGV geometry files along with the detailed documentation are also available for download on the T-Blade3 website and NAX source code on Github website. This design is further optimized to improve the non-axisymmetric geometric distribution against the distorted flow conditions. The design system proposed here helps in exploration of user-specified parametric design space for development of a non-axisymmetric fan stage. Further, since the design system is modular in nature, it can easily be integrated at multiple process levels for other types of turbomachinery design applications.

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DEKAF: an Open-Source Spectral Boundary-Layer Solver

10.35294/tm56 ◽

2020 ◽

Author(s):

Fernando Miró Miró ◽

Koen Groot ◽

Ethan S. Beyak ◽

Alexander J. Moyes ◽

Fabio Pinna ◽

...

Keyword(s):

Boundary Layer ◽

Open Source

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WRF4PALM v1.0: A Mesoscale Dynamical Driver for the Microscale PALM Model System 6.0

10.5194/gmd-2020-306 ◽

2020 ◽

Author(s):

Dongqi Lin ◽

Basit Khan ◽

Marwan Katurji ◽

Leroy Bird ◽

Ricardo Faria ◽

...

Keyword(s):

Boundary Layer ◽

Boundary Conditions ◽

Open Source ◽

Weather Forecasting ◽

Regional Scale ◽

Academic Research ◽

Model System ◽

Small Scale ◽

Meteorological Forcing ◽

Large Eddy Simulation Model

Abstract. A set of Python-based tools, WRF4PALM, has been developed for offline-nesting of the PALM model system 6.0 into the Weather Research and Forecasting (WRF) modelling system. Time-dependent boundary conditions of the atmosphere are critical for accurate representation of microscale meteorological dynamics in high resolution real-data simulations. WRF4PALM generates initial and boundary conditions from WRF outputs to provide time-varying meteorological forcing for PALM. The WRF model has been used across the atmospheric science community for a broad range of multidisciplinary applications. The PALM model system 6.0 is a turbulence-resolving large-eddy simulation model with an additional Reynolds averaged Navier–Stokes (RANS) mode for atmospheric and oceanic boundary layer studies at microscale (Maronga et al., 2020). Currently PALM has the capability to ingest output from the regional scale Consortium for Small-scale Modelling (COSMO) atmospheric prediction model. However, COSMO is not an open source model which requires a licence agreement for operational use or academic research (http://www.cosmo-model.org/). This paper describes and validates the new free and open-source WRF4PALM tools (available on https://github.com/dongqi-DQ/WRF4PALM). Two case studies using WRF4PALM are presented for Christchurch, New Zealand, which demonstrate successful PALM simulations driven by meteorological forcing from WRF outputs. The WRF4PALM tools presented here can potentially be used for micro- and mesoscale studies worldwide, for example in boundary layer studies, air pollution dispersion modelling, wildfire emissions and spread, urban weather forecasting, and agricultural meteorology.

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