Analytical considerations of flow boiling heat transfer in metal-foam filled tubes

Flow boiling in metal-foam filled tube was analytically investigated based on a modified microstructure model, an original boiling heat transfer model and fin analysis for metal foams. Microstructure model of metal foams was established, by which fiber diameter and surface area density were precisely predicted. The heat transfer model for flow boiling in metal foams was based on annular pattern, in which two phase fluid was composed by vapor region in the center of the tube and liquid region near the wall. However, it was assumed that nucleate boiling performed only in the liquid region. Fin analysis and heat transfer network for metal foams were integrated to obtain the convective heat transfer coefficient at interface. The analytical solution was verified by its good agreement with experimental data. The parametric study on heat transfer coefficient and boiling mechanism was also carried out.Peer reviewedFinal Accepted Versio

Analytical considerations of flow boiling heat transfer in metal-foam filled tubes

Flow boiling in metal-foam filled tube was analytically investigated based on a modified microstructure model, an original boiling heat transfer model and fin analysis for metal foams. Microstructure model of metal foams was established, by which fiber diameter and surface area density were precisely predicted. The heat transfer model for flow boiling in metal foams was based on annular pattern, in which two phase fluid was composed by vapor region in the center of the tube and liquid region near the wall. However, it was assumed that nucleate boiling performed only in the liquid region. Fin analysis and heat transfer network for metal foams were integrated to obtain the convective heat transfer coefficient at interface. The analytical solution was verified by its good agreement with experimental data. The parametric study on heat transfer coefficient and boiling mechanism was also carried out

A Dynamic View of the Relationship between Software Development Outsourcing Propensity and Industry Environment

Despite the progress scholars have made on the relationship between IT outsourcing (ITO) and industry environment, our knowledge of this link is still ambiguous and limited. Drawing on recent research on the evolvement of ITO market, we extend our understanding by taking a dynamic view of this issue. Specifically, we focus on software development outsourcing (SDO) and three key elements of industry environment, namely resource munificence, industry concentration and technology change. We argue that the evolvement of ITO market has a moderating effect onthe relationship between SDO propensity and industry environment. Using industry-level data for U.S. private industries from 1998 to 2015, we find that industry environment’s impact on SDO propensity does change with the evolvement of the ITO market. Our findings provide insights on the relationship between SDO propensity and industry environment andindicate the importance of a dynamic view for understanding ITO-related phenomena

Thermal analysis of Phase Change Material Board (PCMB) under weather conditions in the summer

This document is the Accepted Manuscript version of the following article: D. Zhuo, Y. tian, Y. Qu, and Y. K. Chen, ‘Thermal analysis of phase change material board (PCMB) under weather conditions in the summer’, Applied Thermal Engineering, Vol. 99: 690-702, April 2016, doi: https://doi.org/10.1016/j.applthermaleng.2016.01.121. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.Phase Change Material Board (PCMB) has been considered as an effective way to improve the thermal comfort in either new or existing buildings. In this work, firstly the optimal melting temperatures of internal and external PCMB are given, and the optimal heat storage capacities are obtained under the idealised circumstance of considering sinusoidal changes of the room and outdoor temperatures during a day. Secondly, to study the potential energy saving from applying a PCMB, a case study of a lightweight office with real environmental conditions is carried out. The air conditioning is switched on in the model to keep the indoor temperature within thermal comfort. Using the daily energy consumption and daily thermal comfort rate as the performance criteria, the effects of major influencing factors including melting temperature, latent heat and thermal conductivity of PCMB are studied parametrically. The results show that both the external and internal PCMB can achieve better performance when the melting temperature is chosen to be slightly higher than the average indoor air temperature. In the summer, the external PCMB has a better performance than the internal PCMB because the external PCMB works not only as a heat storage system whose function is similar to the internal PCMB, but also as a thermal connection between the outdoor and indoor environment due to its thermal insulation function, which reduces the influence of the changing outdoor environment.Peer reviewedFinal Accepted Versio