scholarly journals Numerical Simulation on the Flow and Heat Transfer of Supercritical CO2 in Sudden Expansion Pipe under Cooling Condition

2015 ◽  
Vol 05 (12) ◽  
pp. 216-222
Author(s):  
超 王
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Cooling Condition ◽  
Sudden Expansion ◽  
Flow And Heat Transfer

Numerical Simulation of Nonlinear Flow and Heat Transfer in a Sudden Expansion and Contraction Channel

2016 ◽  
Author(s):  
M. Yang ◽  
L. Q. Yang ◽  
W. Lu ◽  
L. Li ◽  
Q. X. Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Rectangular Channel ◽  
Flow Region ◽  
Nonlinear Flow ◽  
Forced Flow ◽  
Sudden Expansion ◽  
Symmetric State ◽  
Flow And Heat Transfer

Numerical simulation of forced flow in sudden-expansion followed by sudden-contraction rectangular channel was presented for the whole flow region. The nonlinear flow and heat transfer characteristics were investigated by various Reynolds number and geometrical dimension and the critical Reynolds numbers under different conditions have been calculated. The results show flow and heat transfer from symmetric state to asymmetric state with the increase of Re. When Re<Rec (critical Reynolds number for flow transformation), the symmetric state is stable. On the other hand, when Re ≥Rec, the flow loses stability and from symmetric to asymmetric via a symmetry-breaking bifurcation. And the heat transfer performance have relevant characteristics as fluid flow.

Numerical Simulation of Gas Flow and Heat Transfer in Cross-Wavy Primary Surface Channel for Microtubine Recuperators

2005 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Numerical Study ◽  
High Reliability ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
The Cross

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.

The Effect Analysis of Fin Arrangement on Thermal Hydraulic Performance of a Vehicular Cooler

2013 ◽  
Vol 712-715 ◽  
pp. 1600-1604
Author(s):  
Jing Zhao ◽  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluid Flow ◽  
Design Process ◽  
Simulation Method ◽  
Effect Analysis ◽  
Performance Requirements ◽  
Flow And Heat Transfer ◽  
Stability Structure ◽  
Safety And Stability

The excellent thermal hydraulic performances of coolers are the foundations of vehicular safety and stability. Structure, material, fin type and arrangement all have important effects on the thermal hydraulic performances. Numerical simulation method was adopted in this paper to investigate the effect of fin arrangement. The fluid flow and heat transfer performances were contrasted and analyzed under two different fin arrangements. It was found that fin arrangement effected thermal hydraulic performances severely and during the design process of a cooler, the performance requirements could be met through adjusting fin arrangements.

Sign in / Sign up

Export Citation Format

Share Document