کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
667868 1458718 2016 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A numerical study of heat source reconstruction for the advection–diffusion operator: A conjugate gradient method stabilized with SVD
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
A numerical study of heat source reconstruction for the advection–diffusion operator: A conjugate gradient method stabilized with SVD
چکیده انگلیسی

In order to better understand micromechanical phenomena such as viscoelasticity and plasticity, the thermomechanical viewpoint is of prime importance but requires calorimetric measurements to be performed during a deformation process. Infrared imaging is commonly used to this aim but does not provide direct access to the intrinsic volumetric Thermomechanical Heat Sources (THS). An inverse method is needed to convert temperature fields in the former quantity. The one proposed here relies on a diffusion–advection heat transfer model. Advection is generally not considered in such problems but due to plastic instabilities, a heterogeneous and non-negligible velocity field can play a role in the local heat transfer balance. Discretization of the governing equation is made through appropriate spectral approach. Spatial regularization is then achieved through regular modal truncation. The objective of the inversion process lies in a proper identification of the decomposition coefficients (states) which minimize the residuals. When a Conjugate Gradient Method (CGM) is applied to this nonlinear least square optimization, the use of Karhunen-Loève Decomposition (KLD) or Singular Value Decomposition (SVD) on gradient vectors is shown to produce very good temporal regularization. Two test-cases were explored for noisy data which show that this algorithm performs very well when compared to the Tikhonov penalized conjugate gradient method.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Thermal Sciences - Volume 104, June 2016, Pages 68–85
نویسندگان
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