Vehicle Drive Numerical Analysis Method for Reduced Calculation Load
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Solution Overview
Problem
Conventional numerical analysis methods for vehicle drive units are inefficient due to the high calculation load and time required to analyze the flow field and temperature field simultaneously, as they do not adequately account for the correlation between these fields and the different time scales of their steady states.
Innovation Solution
A method that separates the numerical analysis into steps, first analyzing the flow field until it reaches a quasisteady state, then the temperature field until thermal equilibrium is achieved, and finally analyzing both fields together, with optional additional steps to refine convergence and reduce calculation load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If numerical analysis of flow field and temperature field is performed simultaneously, then analysis accuracy is improved, but calculation time and computational load increase enormously
Solution Approach 1:
The patent segments the simultaneous numerical analysis into three distinct sequential steps: (1) flow field analysis only until steady state, (2) temperature field analysis only until thermal equilibrium, and (3) coupled flow and temperature field analysis. This segmentation allows each step to focus on specific physics, reducing computational complexity and time while maintaining overall analysis accuracy.
Solution Approach 2:
The patent performs preliminary flow field analysis in Step 1 to establish steady flow conditions before initiating temperature field analysis. This preliminary action prepares the system state, allowing subsequent temperature analysis to converge faster and reducing the overall computational burden of the coupled analysis.
2Reliability
If numerical analysis accounts for all three elements (free surface, heat transfer, and moving body movement), then analysis completeness is improved, but calculation load becomes enormous
Solution Approach 1:
The patent segments the complex three-element analysis into manageable phases where different elements are emphasized at different times. Step 1 focuses on free surface and flow, Step 2 on heat transfer with established flow, and Step 3 on the full coupled system. This reduces the computational complexity at each stage while ensuring all elements are ultimately considered.
Solution Approach 2:
The patent performs preliminary analysis of the flow field and free surface behavior before introducing heat transfer analysis. This preliminary establishment of flow patterns and free surface configuration simplifies the subsequent thermal analysis by providing stable boundary conditions and reducing the complexity of the coupled problem.
3Measurement precision
If numerical analysis considers different time scales of flow and temperature steady states, then physical accuracy is improved, but analysis complexity increases
Solution Approach 1:
The patent segments the analysis to respect different time scales by performing flow field analysis first (which reaches steady state quickly) and then temperature field analysis (which reaches thermal equilibrium slowly). This temporal segmentation aligns with the physical reality of different relaxation times while avoiding the complexity of simultaneously resolving both time scales in a single coupled simulation.
Solution Approach 2:
The patent performs preliminary flow field analysis to establish the flow steady state before initiating temperature analysis. This preliminary action acknowledges that flow reaches steady state on a different (shorter) time scale than temperature, and prepares the system in a physically accurate state for the subsequent thermal analysis.
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 approach reduces the calculation load and time required for numerical analysis while ensuring accurate results that account for the correlation between the flow field and temperature field, allowing for more efficient analysis of vehicle drive units.
Implementation Method 1
heat from the moving body is dissipated outside the case
Implementation Method 2
The cooling medium is agitated or the like by the movement of the moving body
Data Source
AI summary
A first analyzing step is a step that conducts numerical analysis of a flow field but does not conduct numerical analysis of a temperature field in a state in which a motor rotor is rotating. The second analyzing step is a step that conducts numerical analysis of both the flow field and the temperature field after the first analyzing step ends. Accordingly, before numerical analysis of the flow field and numerical analysis of the temperature field are conducted together, numerical analysis is conducted first on the flow field in first analyzing step before it is conducted on the temperature field. As a result, compared with when the second analyzing step is executed from the beginning without conducting the first analyzing step, the calculation load of the numerical analysis on an electronic calculator can be reduced, which enables the time that it takes to conduct the numerical analysis to be shortened.