Abstract

Modern trends in the development of chemical technology require a detailed study of the processes of heat and mass transfer in microchannels of various dispersed and microstructured media. This is due to the search for scientifically based ways to improve chemical and biochemical reactors, the need to create new equipment for nuclear energy and the current level of development of regenerative medicine towards the application of additive bioprinting technologies. In this case heat and mass transfer occur under non-stationary conditions, microchannels have a complex geometric shape, transfer can be accompanied by spontaneous convection, possible phase transitions, and chemical and biochemical transformations occur. Mathematical modeling of the outflow of a two-phase liquid-vapor medium from a layer of granular particles was performed using the method of smoothed particles hydrodynamics. The data on the visualization of the flow in the granular bed are presented. The dependences of the mass flow rate of the vapor-liquid mixture depending on the pressure drop in the pipe with a granular bed were established. The study of the occurrence and development of convective flows in the process of unsteady conductive heating of the cell wall with spherical and cylindrical particles has been carried out. Holographic interferometry with immersion optical tomography elements was used to measure temperature fields. Under the conditions of varying the thermophysical properties of the liquid, particles of the granular bed, as well as the magnitude of the supplied heat flux, the mechanism of the influence of filling on the time and nature of microconvection formation near contact spots was studied. A model of mass transfer in a gel was proposed for modeling the process of microorganisms feeding in the bioreactor. The model allows to determine the dynamics of microorganisms growth in the volume of the gel. In the experiments, gels based on agarose and a mixture of agarose and starch were studied. The proposed approach is promising for creating living tissue by bioprinting using gels.

中文翻译：

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结构化介质和凝胶中的不稳定传热和传质

摘要

化学技术发展的现代趋势要求对各种分散和微结构介质的微通道中的传热和传质过程进行详细研究。这是由于正在寻求以科学为基础的方法来改善化学和生化反应堆，需要创建用于核能的新设备以及当前再生医学发展到应用附加生物打印技术的水平。在这种情况下，传热和传质是在非平稳条件下发生的，微通道具有复杂的几何形状，传递过程可能伴有自然对流，可能的相变以及化学和生化转变。使用光滑颗粒流体动力学方法对两相液体蒸气介质从颗粒颗粒层中流出进行数学建模。呈现了颗粒床中流动可视化的数据。建立了气-液混合物的质量流量与颗粒床管道中压降的关系。对球形和圆柱形颗粒对细胞壁进行非稳态传导加热过程中对流的产生和发展进行了研究。具有浸没式光学层析成像元件的全息干涉术用于测量温度场。在改变液体的热物理性质的条件下，颗粒床的颗粒以及所提供的热通量的大小，研究了填充对接触点附近微对流形成时间和性质的影响机理。提出了一种在凝胶中传质的模型，以模拟微生物在生物反应器中的进料过程。该模型可以确定凝胶体积中微生物生长的动力学。在实验中，研究了基于琼脂糖以及琼脂糖和淀粉混合物的凝胶。所提出的方法有望通过使用凝胶进行生物打印来创建活体组织。在实验中，研究了基于琼脂糖以及琼脂糖和淀粉混合物的凝胶。所提出的方法有望通过使用凝胶进行生物打印来创建活体组织。在实验中，研究了基于琼脂糖以及琼脂糖和淀粉混合物的凝胶。所提出的方法有望通过使用凝胶进行生物打印来创建活体组织。