Gang Yang

Bio: Gang Yang is an academic researcher from Taiyuan University of Technology. The author has contributed to research in topics: Nusselt number & Open-channel flow. The author has an hindex of 1, co-authored 2 publications receiving 3 citations.

Numerical Investigation of Flow and Heat Transfer in Corrugated Sinusoidal Wavy Channel

Abstract: A three-dimensional numerical investigation of fluid flow and heat transfer in corrugated sinusoidal wavy channels with uniform wall temperature is performed for air (Pr=0.696) in the low Reynolds numbers regime (Re=40~1000). Constant properties, periodically fully developed laminar flow and heat transfer are considered. The effects of channel plate spacing (e), plate corrugation severity (γ) and air mass flow rate (Re) on flow and heat transfer are discussed. Moreover, the analysis of influence degree of the shape factors on relevant parameters indicates that the effect of shape factor γ is more pronounced than that of e on the friction factor (f) and heat transfer coefficient Nusselt number (Nu). The f and Nu factors increase with the increases of the wave severity (γ) and plate spacing (ff<;0.375). Performance evaluation is carried out by comparison the flow area goodness factor. An optimum goodness is attained on the geometries having the smallest e or the smallest γ. The general relations for f versus Re and shape factors are derived. The local distributions of the vorticity and the Nu are presented.

Numerical Analysis of Transitional Characteristics of Flow and Heat Transfer in Wavy Channels

Abstract: The effects of sinusoidal wavy channel plate spacing, phase shift and Reynolds number(Re) on heat transfer and flow characteristics have been numerically investigated. The calculations are carried out on periodic unit channels with uniform wall temperature for air (Pr=0.696) over Re range of 2000≤Re≤10000. The relative thermal hydraulic performance enhancement is evaluated. Simulation results show that streamlines distortion degree determines flow and heat transfer feature. The maximum Nusselt number(Nu) value is gotten on 0° phase shift channel with maximum plate spacing, and the minimum Nu value is on the 180° phase channel with the same plate spacing. The minimum friction factor(f) value is obtained in 180° phase shift channel with minimum plate spacing, and the maximum f value is gotten in the same phase channel with the minimum plate spacing. The 0° phase channel with the minimum spacing channel has the best performance in all channels.

Thermal performance analysis of plate heat exchanger with different configurations for the heat recovery system in buildings

Abstract: Due to the scarcity of conventional energy sources, a lot of efforts need to be taken regarding energy conservation in the buildings, including heat recovery of air ventilation systems. The present paper focuses on new methods to improve the thermal performance of the heat recovery system by investigating the heat transfer characteristics and the flow development in a flat-plate heat exchanger (FPHE) using three different rib-grooved surfaces (trapezoidal, triangle and semi-circular), the numerical simulations were carried out for uniform wall heat flux equal to 290 W/m2 for air as the working fluid, the Reynolds number varies from 500 to 2000 for three different channel heights. The numerical results indicated that, rib-grooved surfaces have a significant impact on heat transfer enhancement with an increase in the pressure drop through the channel. The effect of rib-grooved patterns on the heat transfer and the fluid flow is more significant in a narrow channel especially for trapezoidal and triangle cor...

Thermal-hydraulic performance modelling of a sine-shaped wavy channel for electronics cooling applications

Abstract: The optimum design of corrugated wavy channels used in mini-channel/micro-channel heat sink applications for minimum pumping power (i.e., minimum pressure drop) and efficient heat transfer is a great challenge in terms of energy savings point of view. In this paper, a commercial solver based on the Finite Element Method (FEM) was used for developing a two dimensional numerical model for a sine-shaped corrugated channel. The effect of channel geometry(spacing ratio ε and waviness parameter γ) on the friction coefficient f, average Nusselt number Nuav, pumping power P.P. and goodness factor G has been carried out for various numerical models at different Reynolds numbers between 100 and 1339. The Nuav parameter clearly increased at Re < 500 with the increasing of γ from 0.024 to 0.21, but with the expense of a higher friction factor.

A study on investigating the thermal and energy saving performances of flat plate heat exchanges (FPHE) with different corrugated channels configurations

Abstract: Due to scarce conventional energy resources, energy consumptions in the buildings occupied a large proportion of the overall energy consumptions. Previous studies investigated the application of the plate heat exchangers in the heat recovery of air ventilation systems. The objective of this paper is to offer new methods to improve the thermal and energy saving performances of flat plate heat exchanges (FPHE) with different corrugated channel configurations and provide a guidance for the optimization design of a novel plate heat exchanger. This paper firstly compared the predicted simulation results with previous experimental results and verified the validation of the numerical methods. Then, this paper used the numerical method to investigate the heat transfer characteristics and the pressure drop as well as the flow distributions in plate heat exchangers with three different corrugated configurations(triangular, semicircle and trapezoidal) and different the channel spacing. The numerical results showed that, corrugated configurations not only had a significant positive impact on heat transfer enhancement, but also led to an increase in the pressure drop through the corrugated channel. It can be seen that the effects of the corrugated channel configurations on the heat transfer and pressure drop were various for different corrugated channels at different Re numbers. In addition, the comparisons of performance factors identified that when the channel spacing was larger, it was more appropriate to choose a triangular corrugated channel at a lower Re number. However, at a higher Re number, selecting the semicircle corrugated channel may be more suitable.