Structural Optimization and Design of Cooling Channel Considering Heat Transfer Deterioration of Endothermic Hydrocarbon Fuel

2008 ◽  
Author(s):  
Weixing Zhou ◽  
Wen Bao ◽  
Daren Yu ◽  
Yanjuan Duan
Keyword(s):  
Heat Transfer ◽  
Structural Optimization ◽  
Hydrocarbon Fuel ◽  
Cooling Channel ◽  
Heat Transfer Deterioration ◽  
Endothermic Hydrocarbon Fuel

Flow and Heat Transfer Characteristics of Supercritical Hydrocarbon Fuel in Mini Channels With Dimples

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Yu Feng ◽  
Jie Cao ◽  
Xin Li ◽  
Silong Zhang ◽  
Jiang Qin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Hydrocarbon Fuel ◽  
Fuel Properties ◽  
Heated Wall ◽  
Cooling Channel ◽  
Heat Transfer Characteristics ◽  
Regenerative Cooling ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Cooling Passage

An idea of using dimples as heat transfer enhancement device in a regenerative cooling passage is proposed to extend the cooling limits for liquid-propellant rocket and scramjet. Numerical studies have been conducted to investigate the flow and heat transfer characteristics of supercritical hydrocarbon fuel in a rectangular cooling channel with dimples applied to the bottom wall. The numerical model is validated through experimental data and accounts for real fuel properties at supercritical pressures. The study shows that the dimples can significantly enhance the convective heat transfer and reduce the heated wall temperature. The average heat transfer rate of the dimpled channel is 1.64 times higher than that of its smooth counterpart while the pressure drop in the dimpled channel is only 1.33 times higher than that of the smooth channel. Furthermore, the thermal stratification in a regenerative cooling channel is alleviated by using dimples. Although heat transfer deterioration of supercritical fluid flow in the trans-critical region cannot be eliminated in the dimpled channel, it can be postponed and greatly weakened. The strong variations of fuel properties are responsible for the local acceleration of fuel and variation of heat transfer performance along the cooling channel.

Heat transfer and cracking performance of endothermic hydrocarbon fuel when it cools a high temperature channel

2016 ◽  
Vol 149 ◽  
pp. 112-120 ◽  
Author(s):  
Lei Yue ◽  
Jianzhou Wu ◽  
Yu Gong ◽  
Jingwei Hou ◽  
Liangping Xiong ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Hydrocarbon Fuel ◽  
Cracking Performance ◽  
Endothermic Hydrocarbon Fuel

scholarly journals Effect of Dimple Depth-Diameter Ratio on the Flow and Heat Transfer Characteristics of Supercritical Hydrocarbon Fuel in Regenerative Cooling Channel

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lihan Li ◽  
Xin Li ◽  
Jiang Qin ◽  
Silong Zhang ◽  
Wen Bao
Keyword(s):  
Heat Transfer ◽  
Pressure Loss ◽  
Hydrocarbon Fuel ◽  
Diameter Ratio ◽  
Fluid Temperature ◽  
Cooling Channel ◽  
Heat Transfer Characteristics ◽  
Regenerative Cooling ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

In order to extend the cooling capacity of thermal protection in various advanced propulsion systems, dimple as an effective heat transfer enhancement device with low-pressure loss has been proposed in regenerative cooling channels of a scramjet. In this paper, numerical simulation is conducted to investigate the effect of the dimple depth-diameter ratio on the flow and heat transfer characteristics of supercritical hydrocarbon fuel inside the cooling channel. The thermal performance factor is adopted to evaluate the local synthetically heat transfer. The results show that increasing the dimple depth-diameter ratio h / d p can significantly reduce wall temperature and enhance the heat transfer inside the cooling channel but simultaneously increase pressure loss. The reason is that when h / d p is rising, the recirculation zones inside dimples would be enlarged and the reattachment point is moving downstream, which enlarge both the high Nu area at rear edge of dimple and the low Nu area in dimple front. In addition, when fluid temperature is nearer the fluid pseudocritical temperature, local acceleration caused by dramatic fluid property change would reduce the increment of heat transfer and also reduce pressure loss. In this study, the optimal depth-diameter ratio of dimple in regenerative cooling channel of hydrocarbon fueled is 0.2.

scholarly journals Experimental investigation of thermodynamic instability of supercritical endothermic hydrocarbon fuel within a small-scale channel

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983028
Author(s):  
Hui Wang ◽  
Wansheng Nie ◽  
Lingyu Su
Keyword(s):  
Heat Transfer ◽  
Kinetic Energy ◽  
Turbulent Flow ◽  
Temperature Drop ◽  
Hydrocarbon Fuel ◽  
Small Scale ◽  
Operating Pressure ◽  
Fuel Temperature ◽  
Transition Flow ◽  
Endothermic Hydrocarbon Fuel

A series of experiments were performed to investigate the thermodynamic instabilities that occur during heating of supercritical endothermic hydrocarbon fuel. A “power–temperature drop” characteristic curve is used to analyze the mechanism of thermodynamic instabilities. The results indicate that the heat-transfer process in a heated tube with increasing heating power can be divided into three periods: stable, developing, and instable; in which, the thermodynamic instabilities are found to occur. When the outlet fuel temperature reaches the pseudo-critical temperature, an acute decrease in fuel density and viscosity causes the flow to change from a transition flow to a turbulent flow, and the sharp increase of heat transfer in turbulent flow increases the thermodynamic instabilities. The intensity of the instability is related to the kinetic energy of the flow and the oscillatory extent. When the mass flow rate is increased from 1.0 to 1.5 g/s, the effect on the flow’s kinetic energy dominates the change in instability which causes the intensity of the instability to increase. While the intensity of the instability decreases with increasing inlet fuel temperature, which results from the decrease of the oscillatory extent. The effects of the operating pressure on the instability are not linear because of the properties of fuel change, obviously with pressure near the critical point.

Heat Transfer Deterioration Onset of Hydrocarbon Fuel at Supercritical Pressure

2017 ◽  
Author(s):  
Zeyuan Cheng ◽  
Zhi Tao ◽  
Jianqin Zhu ◽  
Haiwang Li ◽  
Longyun Wang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flux ◽  
Safety Margin ◽  
Hydrocarbon Fuel ◽  
Supercritical Pressure ◽  
Tube Diameter ◽  
Inlet Temperature ◽  
Operating Pressure ◽  
Heat Transfer Deterioration

The present study pays attention to the pressure effect and geometric effect on heat transfer deterioration onset to supercritical hydrocarbon fuel. Numerical simulation about heat transfer deterioration of hydrocarbon fuel flowing upward in vertical round tubes with various diameter at supercritical pressure was performed. In the simulation, a four-species surrogate model of RP-3 based on the generalized corresponding states law was used and LS low-Reynolds number eddy viscosity turbulence model was selected. For the boundary conditions, inlet temperature was 623K, pressure ranged from 3 to 4MPa, tube diameter varied from 3 to 9mm, and wall heat flux to mass flux ratio changed from 0.07 to 3.18kJ/kg. Comparative analyses between the predicted results and the experimental data revealed the accuracy of thermophysical property model and numerical method. The results indicated that the operating pressure and tube diameter have significant effect to the heat transfer deterioration onset of supercritical hydrocarbon fuel: heat transfer deterioration aggravates and heat transfer deterioration onset moves upstream when the diameter increases. With the increase of operating pressure, heat transfer deterioration becomes weak and the heat transfer deterioration onset moves downstream. Based on current results, several existing correlations of the heat transfer deterioration onset were reviewed and assessed, showing different prediction performance. A new correlation of the threshold value for the ratio between heat flux and mass flux for determining the boundary for heat transfer deterioration under various tube diameter and operating pressure was obtained. The effect of length to diameter ratio on safety margin was discussed. The present study provides the optimization design of regenerative cooling on reducing heat transfer deterioration.

scholarly journals Study on influence of forced vibration of cooling channel on flow and heat transfer of hydrocarbon fuel at supercritical pressure

2021 ◽  
pp. 267-267
Author(s):  
Mantang Chen ◽  
Yin Hu ◽  
Zhixiong Han ◽  
Zilong Peng ◽  
Hao Zan
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Critical Temperature ◽  
Forced Vibration ◽  
Thermal Protection ◽  
Hydrocarbon Fuel ◽  
Supercritical Pressure ◽  
Cooling Channel ◽  
Flow And Heat Transfer ◽  
Stable Conditions

The cooling channel of a scramjet is the fundamental structure of the active thermal protection for an engine. Till now, studies have focused mainly on the steady-state flow and heat transfer process in the cooling channel. However, the vibration intensity of an engine increases sharply as the flight speed increases, because of which, the flow and heat exchange mechanisms based on the cooling channel under stable conditions cannot be applied under vibration. In this study, experimental methods are used to study the characteristics of the forced vibration of a cooling channel on the flow and heat transfer of hydrocarbon fuel at supercritical pressure. In addition, the influences of different vibration frequencies and vibration amplitudes on the flow and heat transfer are analyzed. The research results show that at supercritical pressure, when the fuel temperature is below the critical temperature and the inner wall temperature is above the critical temperature, external vibrations would enhance the heat transfer characteristics of the cooling channel. However, when the pressure and temperature are unstable, the forced vibration of the cooling channel would suppress the instability of temperature and pressure while strengthening the heat exchange.

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