scholarly journals Thermal Management Systems for Civil Aircraft Engines: Review, Challenges and Exploring the Future

2018 ◽  
Vol 8 (11) ◽  
pp. 2044 ◽  
Author(s):  
Soheil Jafari ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Thermal Management ◽  
Cost Effective ◽  
Alternative Methods ◽  
Management Systems ◽  
Engine Efficiency ◽  
Future Challenges ◽  
Aero Engines ◽  
Historical Coverage ◽  
Electrical Components

This paper examines and analytically reviews the thermal management systems proposed over the past six decades for gas turbine civil aero engines. The objective is to establish the evident system shortcomings and to identify the remaining research questions that need to be addressed to enable this important technology to be adopted by next generation of aero engines with complicated designs. Future gas turbine aero engines will be more efficient, compact and will have more electric parts. As a result, more heat will be generated by the different electrical components and avionics. Consequently, alternative methods should be used to dissipate this extra heat as the current thermal management systems are already working on their limits. For this purpose, different structures and ideas in this field are stated in terms of considering engines architecture, the improved engine efficiency, the reduced emission level and the improved fuel economy. This is followed by a historical coverage of the proposed concepts dating back to 1958. Possible thermal management systems development concepts are then classified into four distinct classes: classic, centralized, revolutionary and cost-effective; and critically reviewed from challenges and implementation considerations points of view. Based on this analysis, the potential solutions for dealing with future challenges are proposed including combination of centralized and revolutionary developments and combination of classic and cost-effective developments. The effectiveness of the proposed solutions is also discussed with a complexity-impact correlation analysis.

Lube Oil and Bearing Thermal Management System

2009 ◽  
Author(s):  
Karleine M. Justice ◽  
Jeffrey S. Dalton ◽  
Ian Halliwell ◽  
Stephen Williamson
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Thermal Management ◽  
Gas Turbine Engine ◽  
System Level ◽  
Engine Oil ◽  
Management Systems ◽  
Lubrication System ◽  
Turbine Engine ◽  
Heat Loads

Recent improvements in technology have enabled the development of models capable of capturing performance interactions in the thermal management of air vehicle systems. Such system level models are required for better understanding of integration constraints and interactions, and are becoming increasingly important because of the need for tighter coupling between the components of thermal management systems. The study described here integrates current engine modeling capabilities with an improved, more comprehensive thermal management simulation. More specifically, the current effort evaluates the heat loads associated with the lubrication system of a gas turbine engine. The underlying engine model represents a mid-size, two-spool, subsonic transport engine. The architecture of the model is adaptable to other two-spool turbine engines and missions. Mobil Avrex S Turbo 256 engine oil is used as the lubrication medium. The model consists of five bearing heat loads. Within the engine flowpath, local temperatures and the appropriate rotational speeds are the only parameters pertinent to the heat load calculations. General assumptions have been made to simplify the representation of the lubrication system. Fuel properties into the heat exchanger are assumed. A gear box attached to the high-speed shaft operates both supply pump and scavenge pump and sends compressed air to the oil reservoir. Once the oil is distributed to the bearings, the scavenge pump collects and sends it through a filter and a fuel/oil heat exchanger before it is remixed with the contents of the reservoir. A MATLAB/Simulink modeling environment provides a general approach that may be applied to the thermal management of any engine. As a result of this approach, the new model serves as a starting point for a flexible architecture that can be modified as more detailed specifications or data are made available. In this paper, results from the simple model are compared to a more comprehensive tribology-based analysis. The results demonstrate its successful application to a typical mission, based on very limited data. In general, these results will allow system designers to conduct preliminary analyses and trade studies of gas turbine engine thermal management systems.

scholarly journals Thermal Performance Evaluation in Gas Turbine Aero Engines Accessory Gearbox

2020 ◽  
Vol 5 (3) ◽  
pp. 21
Author(s):  
Soheil Jafari ◽  
Ahmed Bouchareb ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Heat Loss ◽  
Thermal Management ◽  
Thermal Performance ◽  
Sliding Friction ◽  
Methodological Approach ◽  
Rolling Friction ◽  
Power Losses ◽  
Thermal Management System ◽  
Aero Engines

This paper presents a methodological approach for mathematical modelling and physics-based analysis of accessory gearbox (AGB) thermal behavior in gas turbine aero engines. The AGB structure, as one of the main sources of heat in gas turbine aero engines, is firstly described and its power losses will be divided into load-dependent and no-load dependent parts. Different mechanisms of heat generation are then identified and formulated to develop a toolbox for calculation of the churning, sliding friction, and rolling friction losses between contact surfaces of the AGB. The developed tool is also capable of calculating the heat loss mechanisms in different elements of the AGB, such as gears, bearings, and seals. The generated model is used to simulate and analyze the AGB thermal performance in the different flight phases in a typical flight mission, where the obtained results are validated against publicly available data. The analysis of the results confirms the effectiveness of the proposed method to estimate the heat loss values in the AGBs of gas turbine aero engines and to predict the thermal loads of the AGB in different flight phases. The developed tool enables the gas turbine thermal management system designers to deal with the generated heats effectively and in an optimal way.

scholarly journals Design of Cylindrical Thermal Dummy Cell for Development of Lithium-Ion Battery Thermal Management System

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1357
Author(s):  
Wei Li ◽  
Shusheng Xiong ◽  
Xiaojun Zhou ◽  
Wei Shi ◽  
Chongming Wang ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Thermal Management ◽  
Thermal Performance ◽  
Lithium Ion ◽  
Management Systems ◽  
Voltage Source ◽  
Three Dimensional Model ◽  
The Real ◽  
Battery Thermal Management ◽  
Real Cell

This paper aims to design thermal dummy cells (TDCs) that can be used in the development of lithium-ion battery thermal management systems. Based on physical property and geometry of real 18,650 cylindrical cells, a three-dimensional model of TDCs was designed, and it is used to numerically simulate the thermal performance of TDCs. Simulations show that the TDC can mimic the temperature change on the surface of a real cell both at static and dynamic current load. Experimental results show that the rate of heating resistance of TDC is less than 0.43% for temperatures between 27.5 °C and 90.5 °C. Powered by a two-step voltage source of 12 V, the temperature difference of TDCs is 1 °C and 1.6 °C along the circumference and the axial directions, respectively. Powered by a constant voltage source of 6 V, the temperature rising rates on the surface and in the core are higher than 1.9 °C/min. Afterwards, the proposed TDC was used to simulate a real cell for investigating its thermal performance under the New European Driving Cycle (NEDC), and the same tests were conducted using real cells. The test indicates that the TDC surface temperature matches well with that of the real battery during the NEDC test, while the temperature rise of TDC exceeds that of the real battery during the suburban cycle. This paper demonstrates the feasibility of using TDCs to replace real cells, which can greatly improve safety and efficiency for the development of lithium-ion battery thermal management systems.

On the Design of Phase Change Materials based thermal management systems for electronics cooling

2021 ◽  
pp. 117276
Author(s):  
Giulia Righetti ◽  
Claudio Zilio ◽  
Luca Doretti ◽  
Giovanni A. Longo ◽  
Simone Mancin
Keyword(s):  
Phase Change ◽  
Thermal Management ◽  
Phase Change Materials ◽  
Electronics Cooling ◽  
Management Systems

A comparative study between air cooling and liquid cooling thermal management systems for a high-energy lithium-ion battery module

2021 ◽  
Vol 198 ◽  
pp. 117503 ◽  
Author(s):  
Mohsen Akbarzadeh ◽  
Theodoros Kalogiannis ◽  
Joris Jaguemont ◽  
Lu Jin ◽  
Hamidreza Behi ◽  
...  
Keyword(s):  
Comparative Study ◽  
Lithium Ion Battery ◽  
Thermal Management ◽  
Lithium Ion ◽  
High Energy ◽  
Management Systems ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Battery Module

The “Lost Wax” Process of Precision Casting

1950 ◽  
Vol 162 (1) ◽  
pp. 66-74 ◽  
Author(s):  
J. S. Turnbull
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Casting Process ◽  
Alternative Methods ◽  
Casting Technique ◽  
Gas Turbine Blades ◽  
Precision Casting ◽  
Good Surface ◽  
Wax Pattern ◽  
Good Surface Finish

The paper describes a casting process which differs from standard foundry practice in that it uses a wax pattern in a high refractory one-piece mould to produce metal castings with a good surface finish to an accuracy of ±0·002 inch. The process involves making a master pattern in either hard wood or metal, relating it to a soft metal die by precision casting technique, and then the production of wax patterns from the die on an injection machine. Finally, the wax patterns are invested in refractory moulds, the wax is melted out, the mould baked, and the metal component is cast. The “lost wax” process is advantageous in cases where ( a) the metal is unmachinable, or ( b) where the component is of an unmachinable shape, or ( c) where production by other methods takes too long. One of the most common applications is in the manufacture of gas-turbine blades. The tool costs are relatively low compared to the costs involved in alternative methods of manufacture, the die cost being a function of the number of castings required. The production of cheap castings is necessarily dependent on the scrap percentage being kept to a minimum; at present the scrap from the manufacture of gas-turbine blades is less than 30 per cent, and the author surmises that it would not be unreasonable to expect it to be less than 10 per cent in two years' time.

Exergy Analysis of Data Center Thermal Management Systems

2003 ◽  
Author(s):  
Amip J. Shah ◽  
Van P. Carey ◽  
Cullen E. Bash ◽  
Chandrakant D. Patel
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Exergy Analysis ◽  
Thermal Control ◽  
Management Systems ◽  
World Systems ◽  
Sample Data ◽  
Potential Applications ◽  
Temperature Ranges

Data centers today contain more computing and networking equipment than ever before. As a result, a higher amount of cooling is required to maintain facilities within operable temperature ranges. Increasing amounts of resources are spent to achieve thermal control, and tremendous potential benefit lies in the optimization of the cooling process. This paper describes a study performed on data center thermal management systems using the thermodynamic concept of exergy. Specifically, an exergy analysis has been performed on sample data centers in an attempt to identify local and overall inefficiencies within thermal management systems. The development of a model using finite volume analysis has been described, and potential applications to real-world systems have been illustrated. Preliminary results suggest that such an exergy-based analysis can be a useful tool in the design and enhancement of thermal management systems.

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