An Inverse Problem In Research Heat Transfer Enhancement By Optimizing The Longitudinal Vortex Generator

Shape optimization establishes model according to the practical problems inengineering design,and make the necessary improvements basing on the characteristics ofstructure and mechanics of mathematical algorithm, even new and unique structureoptimization algorithm is put forward.Shape optimization inverse problem in heat transfersurface (inverse design) is generally basing on the temperature measured within the objectto calculated object shape image, or according to the boundary surface thermodynamicparameters, such as temperature and heat flux distribution,designing geometry to meet thespecific requirements of thermodynamic parameters.Shape optimization inverse problem isan important part of the heat transfer inverse problem. This project researches heat transferbasic theory using the method of inverse heat transfer problem, to achieve the purpose ofstrengthening heat transfer or reducing the flow resistance,and to exploit new researchareas in the study of the inverse problem.shape optimization inverse problem, to realize the purpose of strengthening heattransfer or reduce the flow resistance in a2d triangular domain with triangle and hemicyclevortex generator shape is examined in the present work by using the conjugate gradientmethod (CGM) and commercial package CFD-FLUENT.When the triangle and hemicyclestructure of vortex generator as original conditions, and other condition is constant, we onlyoptimize the shape of vortex generator to strengthen heat transfer effect or reduce the flowresistance, so as to making the heat exchange equipment has the best heat transfer effect.After that we do local modification of vortex generator to facilitate the processing, and thisshape of vortex generator is defined as the optimum shape.In this paper, the main innovation points: firstly, we not only consider the sensitivityand adjoint equation of the energy equation,but also consider the sensitivity and adjointequation of the dynamic equation in solving conjugate gradient equation and the derivativeof target function. shape optimization of vortex generator will affect the structure of flowfield,which affect the heat transfer effect. So it is necessary to consider the effect ofdynamic equation.In addition, we use the udf programming technique in FLUENT softwareto solve sensitivity equation, adjoint equation and conjugate gradient equation for the firsttime.Then,we use dynamic grid technology to change the shape of vortex generator.Making full use of the existing calculation software to reduce programming workload,decrease the difficulty of work and convenient for data processing.This paper proves the superiority and advancement of the shape optimization inverseproblem in the field of strengthening heat transfer, and verifies the applicability of theconjugate gradient method in the problem of convection diffusion problems and its efficiency in the shape of the inverse problem. Shape optimization inverse problem hasimportant theoretical and practical significance in promoting heat exchange process, puttingforward heat transfer technology, improving the heat exchange equipment, increasing thethermal efficiency, energy saving etc.