Thermal Management System Performance Analysis of Hypersonic Vehicle Based on Closed Brayton Cycle

Author(s):  
Jiang Qin ◽  
Wen Bao ◽  
Weixing Zhou ◽  
Daren Yu
2013 ◽  
Vol 779-780 ◽  
pp. 857-860
Author(s):  
Hua Feng Li ◽  
Xiao Feng Wang ◽  
Xia Ming Kong ◽  
Xing Sheng Lao

A lumped parameter model is developed to study thermal management system performance of underwater vehicle equipping large power proton exchange membrane fuel cell propulsion unit. Fuel cell voltage current characteristic and heat release characteristic are represented by models which take effect of cooling water temperature into considered. Fuel cell stack performance models are validated against experimental data. Cooperated with experimental based models of water pump and heat exchanger, thermal management system performance is analyzed while fuel cell stack fresh cooling water outlet temperature is set to be at a certain value. The results show that inlet seawater temperature variation has little effect on opening of regulating valve, but engine power output variation results in notably regulating valve opening fluctuation. Modeling results would be employed in design of a underwater vehicle 300kW fuel cell engine system..


Author(s):  
Junkui (Allen) Huang ◽  
Shervin Shoai Naini ◽  
Richard Miller ◽  
Denise Rizzo ◽  
Katie Sebeck ◽  
...  

Enhanced battery pack cooling remains an open thermal management challenge in hybrid electric vehicle applications. A robust cooling system should maintain the battery pack core temperature within a prescribed operating range to improve system performance, durability, and reliability while minimizing power consumption. This paper proposes a smart battery thermal management system utilizing heat pipes as a thermal bus to efficiently remove heat. The system couples a standard air conditioning system with traditional ambient air ventilation. The two loops can run independently or in tandem to achieve the desired control. A nonlinear model predictive controller was developed to maintain the battery core temperature within a designated range using the compressor and fan speeds as the control inputs. A mathematical battery thermal model was developed to estimate the core and surface temperatures. The system performance and power requirements were evaluated for various driving cycles and ambient conditions. Numerical results showed that the proposed cooling system can regulate the battery core temperature within the desired temperature range (maximum tracking error of 2.1°C) while compensating for ambient temperature conditions using a suitable cooling strategy. The simulation results showed the ability to remove up to 1135 kJ of heat. The simulation also presents the power consumed by system components under varying modes and ambient conditions.


Author(s):  
Martin P. DeSimio ◽  
Brandon M. Hencey ◽  
Adam C. Parry

Modern tactical aircraft subsystems face challenging weight and volume limitations. In addition, power and thermal subsystems have grown increasingly flight critical with each successive generation. Consequently, next generation power and thermal systems must reliably operate under narrower margins to enable electrically and thermally demanding capabilities, such as directed energy weapons. The ability to narrow these margins is ultimately limited by the ability to guarantee mission objectives despite variations and uncertainty in power and thermal system performance. This paper demonstrates online prognostic methods applied to a fuel thermal management system. Furthermore, this paper highlights the need for future research to quantify the effects on mission objectives caused by discrepancies between nominal and actual conditions for aircraft designs based on models of highly integrated systems.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yi-Hsuan Hung ◽  
Jyun-Hong Chen ◽  
Tun-Ping Teng

A thermal management system using alumina (Al2O3)/water as the nanofluid for green power sources was experimentally assessed in this paper. Basic thermal principles and formulas were utilized to evaluate the performance of an air-cooled heat exchanger. The Al2O3/water nanofluid was produced at the concentrations of 0.5, 1.0, and 1.5 wt.%. The testing conditions of this experiments were above three concentrations, five coolant flow rates (0.8, 1.2, 1.6, 2.0, and 2.4 L/min.), and three heating powers (50, 100, and 150 W). Firstly, basic properties of nanoparticles were analyzed. Fundamental relationships of the Al2O3/water nanofluid with respect to temperatures and concentrations were measured such as: viscosity, density, and specific heat. Next, an innovative concept named efficiency factor (EF) was proposed to quantitatively evaluate the thermal system performance. The enhancement of thermal system performance compared with distilled water was then defined as an efficiency factor ratio (REF). The experimental results demonstrated that the efficiency factor ratios were optimal at low flow rate (0.8 L/min.) and low concentration (0.5%). Values ofREFwere all below 1.0 at high flow rates (1.2–2.4 L/min.). This research points out the direction of optimizing a thermal management system for green energy sources in the near future.


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