Investigation Of Efects On Flow And Heat Transfer In Primary Surface Channel

With the development of technology and the adjustment of Energy and power structure during global scope, it has become a new hotspot of study on enhancing heat transfer technology for satisfying manufacturing demand of high-efficient, compact, low pressure-loss and low noise heat exchangers that developing the excellent exchanging heat effect and low pressure-loss heat exchanger surface. The enhancement heat transfer of Primary Surface is put forward and developed under this background. Many domestic and foreign literatures had proven by means of experimental and numerical simulation that the Primary Surface can strengthen heat transfer through inducing fluid spontaneous vibration, initiating flow instability and urging fluid disturbance and mix.Modeling software GAMBIT is used to establish two-dimensional numerical model of the Primary Surface passage under five different structure types. Numerical simulation software FLUENT6.0 is used to simulate the flow and heat transfer of air inside two-dimensional periodically wavy channel. The comparison of different structure types with constant wall temperature on flow and heat transfer were made, and the effects of the parameters of convergent-divergent ratio, wave height and plate spacing on the flow and heat transfer performances were analyzed for different structure types. Factors of shearing stress, vorticity, fluid creating isolation and reattachment on curved surface are analyzed. The paper obtains streamline distribution, temperature distribution, shearing stress distribution, Nusser number and friction coefficient of different structure types channel at the different Reynolds number. The colligating performance of all kinds of channels was compared, and the flow and heat transfer characteristics in different channels were disclosed. As a result, these provides scientific basis for best matching on heat transfer and flow.The results showed that: the comprehensive properties of every channel first increased than decreased when the Reynolds number increased, the low Reynolds number's comprehensive properties of channel is lower than large Reynolds number's, the comprehensive properties of every channel is improved when the Reynolds number is more than 1000. When corrugated plate is reversed arranged, the comprehensive properties of every channel studied in this paper, the properties of sinusoidal channel is the best, the properties of triangle's takes second place, and the properties of rectangular is the poorest, but the properties of sinusoidal channel is most easily influenced by Reynolds number. When corrugated plate is arranged in the same direct, the properties of tangent linear channel and triangle is the best, but the properties of elliptic channel is most unstable at low Reynolds number. In addition the flow, the heat exchange, the wall shear stress and drag coefficient is influenced by parametric variation of every channel. Every channel is properly elected according to different needs and different work condition.