مرجان شريفي

In most natural and man-made systems, the concept of heat transfer is of great importance. In order to correctly eva‎luate these systems using engineering methods, it is necessary to consider the interaction of different heat transfer mechanisms, including conduction, displacement, and radiation, to obtain results in accordance with the physics of the problem. This causes complexities to enter the problem and in many cases, it will not be possible to solve analytically for the mathematical equations governing such problems. As a result, it is inevitable to use numerical methods to solve these equations. In recent years, due to its advantages, the Boltzmann network method has found many applications in investigating heat transfer problems. After proving the accuracy and correctness of the results of this method to investigate conduction and displacement heat transfer, in the last decade, the use of this network to investigate radiation and its performance in this field has become an attractive topic for researchers. Because in problems involving radiant heat transfer in combination with conduction or displacement, it was common to use different methods to investigate the two existing mechanisms. As a result, the need to couple these methods for data exchange is certain, which can be computationally expensive. In the current research, in order to develop the application of the Boltzmann network method in the simulation of combined conduction-radiation heat transfer problems, the performance of this method has been investigated in irregular geometries including curved boundaries. The geometries used in this simulation were generated through the passive zone method. The results of the developed LBM-LBM code are compared with the results of FVM-DOM on similar geometries, but produced by the multiple blocks method. This comparison indicates that the developed code has good accuracy for predicting temperature distribution in geometries including curved boundary and its accuracy increases with the increase of conduction-radiation parameter. In examining the heat flux using LBM-LBM, discrepancies are observed in the results of the two methods, which are mainly caused by the small number of links in the D_2 Q_8 network arrangement for the radiation algorithm, and it is predicted that using networks with more connections this case be fixed In general, the developed code is able to predict the radiation behavior in geometries including curved boundary with good accuracy, especially for larger conduction-radiation parameter.

روش شبكه بولتزمان , انتقال حرارت تركيبي , رسانش , تابش , هندسه نامنظم , روش ناحيه غيرفعال , روش راستاهاي مجزا

Lattice Boltzmann method , Combined heat transfer , Conduction , Radiation , Irregular geometry , Blocked-off method , Discrete ordinate method

Marjan Sharifi

Majid Siavashi