An efficient goal based reduced order model approach for targeted adaptive observations
File(s)
Author(s)
Fang, F
Pain, C
Navon, I
Xiao, D
Type
Journal Article
Abstract
An efficient adjoint sensitivity technique for optimally collecting targeted observations is presented. The targeting technique incorporates dynamical information from the numerical model predictions to identify when, where, and what types of observations would provide the greatest improvement to specific model forecasts at a future time. A functional (goal) is defined to measure what is considered important in modelling problems. The adjoint sensitivity technique is used to identify the impact of observations on the predictive accuracy of the functional, then placing the sensors at the locations with high impacts. The adaptive (goal) observation technique developed here has the following features: (1) over existing targeted observation techniques, its novelty lies in that the interpolation error of numerical results is introduced to the functional (goal) which ensures the measurements are a distance apart; (2) the use of proper orthogonal decomposition (POD) and reduced order modeling (ROM) for both the forward and backward simulations, thus reducing the computational cost; and (3) the use of unstructured meshes. The targeted adaptive observation technique, is developed here within an unstructured mesh finite element model (Fluidity). In this work, a POD ROM is used to form the reduced order forward model by projecting the original complex model from a high dimensional space onto a reduced order space. The reduced order adjoint model is then constructed directly from the reduced order forward model. This efficient adaptive observation technique has been validated with two test cases: a model of an ocean Gyre and a model of 2D urban street canyon flows.
Date Issued
2016-07-12
Date Acceptance
2016-05-31
Citation
International Journal for Numerical Methods in Fluids, 2016, 83 (3), pp.263-275
ISSN
0271-2091
Publisher
Wiley
Start Page
263
End Page
275
Journal / Book Title
International Journal for Numerical Methods in Fluids
Volume
83
Issue
3
Copyright Statement
© 2016 John Wiley & Sons, Ltd. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/fld.4265
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Grant Number
EP/I00405X/1
RG80519
Subjects
Science & Technology
Technology
Physical Sciences
Computer Science, Interdisciplinary Applications
Mathematics, Interdisciplinary Applications
Mechanics
Physics, Fluids & Plasmas
Computer Science
Mathematics
Physics
adaptive observations
finite element
proper orthogonal decomposition
reduced order modelling
4D-VAR DATA ASSIMILATION
VARIATIONAL DATA ASSIMILATION
OBSERVATION IMPACT
AIR-QUALITY
OPTIMIZATION
LOCATION
SENSORS
ERROR
OCEAN
FLOW
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Applied Mathematics
Publication Status
Published