RAM-C Aerodynamic Modeling Feedback Loop for eVTOL

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Solution Overview

Problem

Traditional aerodynamic modeling methods for complex aircraft, such as eVTOL and UAM systems, face challenges in accurately predicting forces and moments under rapidly changing flight conditions, leading to increased computational costs and resource demands, and often result in lower fidelity models that fail to capture nonlinear interactions.

Innovation Solution

The Rapid Aero Modeling (RAM) process, specifically RAM-C, uses computational fluid dynamics (CFD) and feedback loops to automatically generate aerodynamic models by determining required fidelity criteria, forming data test blocks, and iteratively refining models to meet user-defined prediction error requirements, allowing for efficient and accurate estimation of aerodynamic forces and moments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional CFD programs are used to determine aerodynamic forces for each flight condition, then measurement precision is improved, but productivity deteriorates because the computation cannot keep up with rapidly changing flight conditions

Engineering Contradiction:
Improveaerodynamic force prediction accuracyVSAvoidcomputation speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent creates aerodynamic models in advance using CFD simulations or wind tunnel data before actual flight simulations. These pre-computed models capture the aerodynamic characteristics across a range of flight conditions, allowing rapid prediction during simulations without performing real-time CFD calculations. This preliminary action resolves the contradiction by preparing accurate aerodynamic data beforehand, enabling both high precision and fast computation speed during actual use.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If polynomial models are estimated from wind tunnel tests or CFD simulations to enable rapid prediction, then productivity is improved, but measurement precision deteriorates because the accuracy of predictions cannot be guaranteed

Engineering Contradiction:
Improvesimulation speedVSAvoidprediction accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the aerodynamic models are validated against a separate validation dataset that was not used during model creation. This validation process checks prediction accuracy and provides feedback on model quality. If the model accuracy is insufficient, the system can identify which flight conditions or parameters need improved modeling. This feedback loop ensures that the rapid polynomial models maintain guaranteed accuracy levels while enabling fast simulations.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If traditional testing methods are used for complex aircraft with aerodynamic nonlinearities, then measurement precision may be improved, but device complexity increases and key factor interactions are missed

Engineering Contradiction:
Improveaerodynamic model fidelityVSAvoidtesting and modeling complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the aerodynamic modeling process into distinct phases: data collection from CFD or wind tunnel tests, model creation using polynomial fitting, and validation against independent test data. This segmentation allows systematic handling of complex aircraft with multiple nonlinear factors by breaking down the overall modeling task into manageable steps. Each phase can be optimized independently, reducing overall complexity while maintaining high model fidelity for capturing key factor interactions.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11983467B2Rapid aero modeling for computational experiments (RAM-C)
Publication Date: 2024.05.14 UNITED STATES OF AMERICA AS REPRESENTED BY THE ADMINISTRATOR NAT AERONAUTICS & SPACE ADMINISTRATION
  • US11983467B2 patent drawing
  • US11983467B2 patent drawing
  • US11983467B2 patent drawing

AI summary

A Rapid Aero Modeling program and process may be applied to computational experiments such as computational fluid dynamics (CFD) programs to obtain aerodynamic models which may be in the form of polynomial equations. The program and process may be utilized to estimate (develop) aerodynamic models appropriate for flight dynamics studies, simulations, and the like. Feedback loops are provided around computational codes to rapidly guide testing toward aerodynamic models that meet user-defined fidelity criteria. A user has the freedom to choose a specific level of fidelity in terms of prediction error, in advance of a CFD test (computation).