Aircraft Propulsion Cooling with Thermal Buffer Pre-Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical aircraft propulsion systems face challenges in optimizing the sizing of ram air channels for cooling before, during, and after take-off, leading to inefficiencies and performance penalties.
Innovation Solution
A cooling system with a coolant circuit that includes a bypass portion and heat exchangers, allowing coolant temperature regulation through a variable speed pump and fans, enabling overcooling before take-off to act as a thermal buffer, thereby reducing the need for large ram air channels during critical phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sizing of ram air channels is increased to improve cooling before and during take-off, then the cooling capability is improved, but the global performance of the aircraft is penalized due to increased drag and weight
Solution Approach 1:
The system pre-cools the coolant in a thermal buffer tank before take-off, storing cold thermal energy that can be used during the critical take-off phase when airspeed is low and ram air cooling is ineffective. This preliminary cooling action allows the aircraft to use smaller ram air channels while maintaining adequate cooling capability throughout all flight phases.
2Productivity
If the sizing of ram air channels is reduced to improve aircraft performance, then the global performance is improved, but the cooling capability before and during take-off is affected
Solution Approach 1:
The thermal buffer tank is pre-filled with cold coolant before take-off, creating a reservoir of cold thermal energy that compensates for the reduced cooling capability of smaller ram air channels during the critical low-speed take-off phase.
Solution Approach 2:
The thermal buffer tank acts as an intermediary thermal storage device between the coolant system and the energy source, decoupling the cooling demand during take-off from the ram air channel sizing, thereby allowing optimized channel dimensions without compromising cooling reliability.
3Reliability
If the coolant temperature is reduced below operating temperature before take-off, then a thermal buffer is created for take-off phase, but additional cooling energy is consumed
Solution Approach 1:
The system utilizes the thermal mass and heat capacity of the coolant as a thermal buffer, effectively using the coolant's ability to store and release thermal energy during phase-like temperature transitions to meet cooling demands during take-off without requiring continuous high-energy cooling input.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system optimizes coolant temperature management, reducing the size of ram air channels and enhancing aircraft performance by delaying the need for high-speed cooling until the aircraft reaches higher speeds, thus maintaining fuel cell reliability and efficiency.
Implementation Method 1
one or more heat exchangers for cooling a coolant
Implementation Method 2
the aircraft comprises channels through which ram air flows
Implementation Method 3
one or more air channels comprises one or more fans
Implementation Method 4
one or more air channels inside which the one or more heat exchangers are placed
Implementation Method 5
the coolant circuit comprises a variable speed pump and a switch
Implementation Method 6
decreasing the temperature of a portion of a coolant below an operating temperature, acting this portion of the coolant as a thermal buffer
Data Source
AI summary
A method for cooling an electrical aircraft propulsion system includes decreasing a temperature of a portion of a coolant below an operating temperature, acting this portion of the coolant as a thermal buffer, and maintaining a rest of the coolant at the operating temperature.