Aumerical modelling of steady axisymmetric viscous external flow and heat and mass transfer at the surface of an inviscid gas bubble has been carried out. A numerical method based on a velocity–pressure formulation combined with a. nite-volume discretization of the Navier–Stokes related equations written in a non-orthogonal body-. tted coordinate (BFC) is employed. The method has been validated by calculating the uid ow with heat and mass transfer around the surface of a rigid sphere and comparing with published data that are well regarded as benchmark solutions. The feasibility of the method for simulating a gas bubble problem is tested by calculating. elds around an inviscid fluid sphere (or a pseudo-bubble) at similar conditions to the rigid sphere. On this basis, a deformable gas bubble at Sc 500 and Pr 2 is studied. The. elds of flow, temperature, and concentration change with Reynolds and Weber numbers are simulated. It is found that the interactions between the. elds and the deformation of the bubble interface are signi. cant.

A numerical investigation on steady external axisymmetric viscous flow and heat and mass transfer at the surface of an inviscid spherical gas bubble has been carried out. The numerical code developed for this study employs a velocity-pressure formulation combined with a finite-volume discretisation of the Navier-Stokes species continuity and energy equations written in a non-orthogonal body-fitted coordinates (BFCs). The code is validated against two types of standard flows, namely the flow through a diverging Roache channel, and the flow, and heat and mass transfers around a rigid sphere for the Reynolds number range from 1 to 300. On the same basis, the external flow, heat and mass transfer at the surface of an inviscid spherical bubble is simulated numerically and compared with the results for a similar rigid sphere. There are distinguishable differences in both the flow fields and concentration (or temperature) distributions around the bubble and the sphere.

In this paper, the interfacial transport characteristics to or from spheroidal bubbles are studied numerically and the results of numerical simulations are reported. The numerical modelling uses the SIMPLE method with a non-orthogonal, boundary fitted staggered grid. The aim of this paper is to provide an understanding of the interfacial transport characteristics of inviscid spheroidal bubbles, of different geometric parameters, rising in a stagnant hot or bi-solution liquid. The flow and concentration (or temperature) fields around bubbles and similarly sized rigid spheroids are computed. Detailed analyses of the pressure and vorticity distributions at surfaces of the inviscid spheroidal bubbles are made and compared with those of similar rigid spheroids. Drag coefficients for and wake lengths behind rigid spheroids and inviscid spheroidal bubbles are also presented. Local and mean Sherwood numbers and Nusselt numbers at bubble and rigid spheroid surfaces are compared, as well as their change with the Reynolds and Schmidt numbers and geometric parameters.

This paper is concerned with a numerical study on evolution of a deformed bubble and propagation of the fields around the bubble. The model uses a numerical procedure with the direct-predictor method and the alternating dependent variables (ADV) skill developed by Li and Yan. The aim of this paper is to study the characteristics of interfacial transport for a deformed inviscid bubble rising in a quiescent hot or bi-solution liquid. The effects of the bubble deformation on temperature and concentration fields are calculated and simulated. The results demonstrate that the current numerical procedure is effective for solving such unsteady deformation problems of bubble accompanied with heat and mass transfer.

采用结构化程序设计方法，建立了锅炉热力计算与火用分析通用软件.本应用软件可对锅炉及各受热面进行热力计算、热平衡计算及火用损失分析;可对锅炉变工况、变煤种情况进行分析计算;还可进行各受热面合理布置与改造的设计计算.目的是了解和减少锅炉的热损失及火用损失，寻求最佳运行工况，提高能量利用率.通过对典型煤粉炉的多工况计算考核，表明软件具有较强的实用性和可靠性.