Numerical Modeling of Neutrally-Stable and Sustainable Atmospheric Boundary Layer for the Wind Load Estimation on an Offshore Platform

2018 ◽  
Author(s):  
Jang Whan Kim ◽  
Hyunchul Jang ◽  
Wei Xu ◽  
Zhirong Shen ◽  
Mustafa Kara ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Numerical Modeling ◽  
Wind Profile ◽  
Task Force ◽  
Wind Load ◽  
Load Estimation ◽  
Joint Effort ◽  
Cfd Simulations ◽  
Research Institutes ◽  
Offshore Industry

This paper summarizes a joint effort among operators, class societies, research institutes, shipyards, and engineering companies to verify a common modeling practice to generate a sustainable wind profile in CFD simulations for wind tunnel tests. The same numerical guideline is applied to various CFD software commonly used in the offshore industry. This is part of the effort from the CFD Task Force under the SNAME OC-8 Panel, “Guidance on Wind Technologies.” The verification results show that the sustainable wind profile can be generated within 1% tolerance from the target wind profile, for all five CFD software participated. The uncertainties in the wind load are also contained within 4% for the semisubmersible hull tested in this study with a traditional turbulence model and the 1%-tolerance wind profile, regardless of the CFD software.

Numerical Modeling of Sustainable Atmospheric Boundary Layer for Offshore Floaters

2021 ◽  
Author(s):  
Jang Whan Kim ◽  
Hyunchul Jang ◽  
Seongmo Yeon ◽  
Hyunjoe Kim
Keyword(s):  
Numerical Modeling ◽  
Wind Profile ◽  
Task Force ◽  
Wind Load ◽  
Development Project ◽  
Cfd Modeling ◽  
Navier Stokes ◽  
Science Data ◽  
Cfd Simulations ◽  
Wind Profiles

Abstract Wind load is one of the major design load considerations for the hull and mooring of offshore floating facilities. The first step to minimize the uncertainties in wind load is generating an accurate wind profile that satisfies design requirements. Recently, there was a joint-industry effort to develop CFD modeling practices on wind-load estimation in SNAME OC-8 CFD Task Force (OMAE2018-78699). The Task Force developed the modeling practice for the NPD (Norwegian Petroleum Directorate) model commonly used for offshore platform design, and several independent participants in the Task Force successfully validated the practice for a topsides of a semi-submersible platform. The sustainable wind profile was able to be generated within 1% tolerance of the target wind profile, and the calculated wind loads on the topsides from CFD simulations were close to the model test data with low uncertainty levels. In the present study, the numerical modeling for the sustainable ABL is extended to other popular wind models such as the ESDU (Engineering Science Data Unit) and the power-law models. The study is a part of a joint-development project between TechnipFMC, Chevron, and Samsung Heavy Industries. The analytic or numerical formulae of wind speed and turbulent quantities for several RANS (Reynolds-Averaged Navier-Stokes) models are derived for the wind models, and the sustainability of wind profiles are verified.

scholarly journals Characteristics of the vertical wind profile for wind load estimation

1990 ◽  
Vol 1990 (45) ◽  
pp. 23-43 ◽  
Author(s):  
Hang CHOI ◽  
Jun KANDA
Keyword(s):  
Wind Profile ◽  
Wind Load ◽  
Vertical Wind ◽  
Load Estimation

Numerical Modeling Practice and Verification of the Wind Load Estimation for FPSO and Semi-Submersible

2019 ◽  
Author(s):  
SeongMo Yeon ◽  
Hyunchul Jang ◽  
Jang Whan Kim ◽  
JooSung Kim ◽  
Bo Woo Nam ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Model Test ◽  
Wind Profile ◽  
Domain Size ◽  
Wind Load ◽  
Computational Domain ◽  
Ocean Engineering ◽  
Blind Test ◽  
Floating Structures ◽  
Modeling Practice

Abstract This paper summarizes a joint effort, TESK JDP, initiated by TechnipFMC, ExxonMobil Upstream Research Company (EMURC), Samsung Heavy Industries (SHI) and Korea Research Institute of Ships & Ocean Engineering (KRISO) in order to develop reliable modeling practices for the application of Computational Fluid Dynamics (CFD) to the design of the offshore floating structures. The modeling practice for the wind load on offshore floating structures, which was one of the topics in this JDP, was studied and verified against model test results. The wind load on the offshore floating structures mostly depends on the shape of the wind profile rather than the design wind speed. Much weight is put on the generation and retainment of the wind profile within the computational domain. The modeling practice for generating the wind profile referred to as sustainable atmospheric boundary layer (ABL) or horizontally homogeneous turbulent boundary layer (HHTBL) as well as domain size, mesh strategy, turbulence model are used to perform wind load simulations for a semi-submersible and FPSO respectively as a blind test between JDP members. In order to minimize uncertainties from geometric similarity, special care was taken during the simulation and model test for the FPSO due to the complicated top side modules. Given the modeling practice, the results are compared between JDP members and show consistent tendency. Also, a good agreement was observed for the hydrodynamic coefficients of the wind load for both the FPSO and semi-submersible.

scholarly journals Wind profile correction algorithm based on Atmospheric Boundary Layer stability profile

2021 ◽  
Author(s):  
Francisco Albuquerque Neto ◽  
Vinicius Almeida ◽  
Julia Carelli
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Wind Profile ◽  
Horizontal Wind ◽  
Boundary Layer Stability ◽  
Correction Algorithm ◽  
Horizontal Wind Speed ◽  
Study Region ◽  
Profile Correction ◽  
Wind Profiles

<p>In recent years, the use of radar wind profilers (RWP) at airports has grown significantly with the aim of supporting decision makers to maintain the safety of aircraft landings and takeoffs.</p><p>The RWP provide vertical profiles of averaged horizontal wind speed and direction and vertical wind velocity for the entire Atmospheric Boundary Layer (ABL) and beyond. In addition, RWP with Radio-Acoustic Sounding System (RASS) are able to retrieve virtual temperature profiles in the ABL.</p><p>RWP data evaluation is usually based on the so-called Doppler Beam Swinging method (DBS) which assumes homogeneity and stationarity of the wind field. Often, transient eddies violate this homogeneity and stationarity requirement. Hence, incorrect wind profiles can relate to transient eddies and present a problem for the forecast of high-impact weather phenomena in airports. This work intends to provide a method for removing outliers in such profiles based on historical data and other variables related to the Atmospheric Boundary Layer stability profile in the study region.</p><p>For this study, a dataset of almost one year retrieved from a RWP LAP3000 with RASS Extension is used for a wind profile correction algorithm development.</p><p>The algorithm consists of the detection of outliers in the wind profiles based on the thermodynamic structure of the ABL and the generation of the corrected profiles.</p><p>Results show that the algorithm is capable of identifying and correcting unrealistic variations in speed caused by transient eddies. The method can be applied as a complement to the RWP data processing for better data reliability.</p><p> </p><p>Keywords: atmospheric boundary layer; stability profile; wind profile</p>

An Idealized Mean Wind Profile for the Atmospheric Boundary Layer

2004 ◽  
Vol 110 (2) ◽  
pp. 281-299 ◽  
Author(s):  
John D. Wilson ◽  
Thomas K. Flesch
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Wind Profile

Numerical Modeling of Turbulent Transitional MHD Flow for Boundary Layer Control

2013 ◽  
Author(s):  
Tiago Machado ◽  
Jose C. Pascoa ◽  
Francisco Brojo ◽  
Carlos Xisto
Keyword(s):  
Boundary Layer ◽  
Numerical Modeling ◽  
Mhd Flow ◽  
Boundary Layer Control ◽  
Layer Control
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