Train Underbody Airflow Control for Aerodynamic Lift Stability

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Solution Overview

Problem

Existing maglev trains lack the ability to actively and precisely control aerodynamic lift according to varying operating conditions, which affects stability, safety, and energy efficiency.

Innovation Solution

A railway vehicle with an aerodynamic lift control device that includes a bottom air blowing and sucking mechanism, utilizing aerodynamic lift regulation air blowers and ducts to adjust pressure distribution at the train's bottom, enabling precise control of aerodynamic lift through positive or negative airflows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the running speed of the train is increased, then the transportation efficiency is improved, but the aerodynamic lift increases which affects operation safety

Engineering Contradiction:
Improverunning speedVSAvoidoperation safety
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies aerodynamic lift control devices that can dynamically adjust the aerodynamic lift characteristics of the train body. By using adjustable aerodynamic components (such as flaps, panels, or variable geometry structures), the train can modify its lift coefficient in real-time based on operating conditions, allowing high-speed operation while maintaining safety through active aerodynamic management.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes aerodynamic parameters (such as lift coefficient, drag coefficient) by modifying the train's aerodynamic configuration. This can be achieved through variable geometry components that adjust the effective aerodynamic surface area or shape, thereby controlling the magnitude of aerodynamic lift and drag forces acting on the train at different speeds.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the aerodynamic lift is increased to improve levitation control, then the levitation performance is improved, but the energy consumption increases

Engineering Contradiction:
Improvelevitation controlVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs passive aerodynamic lift generation where the train's motion through air naturally produces the required lift force without requiring additional energy input from onboard systems. The aerodynamic shape and configuration are designed to convert kinetic energy from the train's forward motion into useful aerodynamic lift, eliminating the need for active energy-consuming levitation systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces active mechanical or electromagnetic levitation systems with passive aerodynamic lift mechanisms. Instead of using energy-intensive motors or magnetic fields to generate lift, the system uses the train's forward motion and aerodynamic design to generate lift forces, thereby substituting a high-energy mechanical system with a low-energy aerodynamic solution.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the train body shape is modified to control aerodynamic lift, then the aerodynamic performance is improved, but the design complexity and cost increase

Engineering Contradiction:
Improveaerodynamic performanceVSAvoiddesign complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the aerodynamic control function into separate, modular components rather than requiring complete redesign of the train body. Aerodynamic control devices are implemented as distinct elements (such as adjustable panels, flaps, or attachments) that can be independently designed, tested, and adjusted, reducing overall design complexity while achieving the desired aerodynamic performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs aerodynamic components that serve multiple functions: they generate aerodynamic lift, reduce drag, and can be adjusted for different operating conditions. These multi-functional aerodynamic elements are integrated into the existing train structure, allowing a single design modification to address multiple aerodynamic requirements simultaneously, thereby reducing overall design complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The device allows for stable, reliable, and energy-efficient operation by quantitatively controlling aerodynamic lift, reducing energy consumption and maintaining stability during high-speed travel.

Implementation Method 1

The aerodynamic lift of the maglev train has a great impact on a levitation control system and an operation safety of the train. Generally, the higher the running speed of the train is, the greater the aerodynamic lift is.

Methodology Applied
Scientific EffectAerodynamic lift: Aerofoil

Implementation Method 2

a pressure distribution at the bottom of the train is improved by mounting a bottom air blowing and sucking device according to the characteristics of a flow field at the bottom of the train

Methodology Applied
Scientific EffectPressure distribution: Pressure Gradient

Data Source

PatentEP4086104B1Railway vehicle with aerodynamic lift control device
Publication Date: 2025.10.15 CRRC QINGDAO SIFANG CO LTD
  • EP4086104B1 patent drawingFigure 1~3
  • EP4086104B1 patent drawingFigure 4
  • EP4086104B1 patent drawingFigure 5

AI summary

A railway vehicle with an aerodynamic lift control device. An equipment compartment is formed between a vehicle body bottom plate at the bottom of a vehicle body and a passenger room floor, and the aerodynamic lift control device is provided in the equipment compartment; the aerodynamic lift control device comprises an aerodynamic lift regulation fan and aerodynamic lift air ducts, and an aerodynamic lift regulation air port located within the aerodynamic lift control range is formed in the vehicle body bottom plate; one end of each aerodynamic lift regulating air duct communicates with the aerodynamic lift regulation air port, and the other end communicates with the aerodynamic lift regulating fan; and the aerodynamic lift regulation fan changes the pressure distribution form of the bottom of the train by blowing positive pressure airflow or sucking negative pressure airflow. According to the railway vehicle, the bottom pressure distribution of the train is improved by installing the bottom air blowing and sucking device according to the characteristics of the bottom flow field of the train, so that active and accurate control of aerodynamic lift borne by the train is realized.