Contra-Rotating Fan Cooling for Dynamometer High Power Testing

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Solution Overview

Problem

As vehicle engines generate higher powers and torques, the heat generated by power-absorbing means during dynamometer testing becomes difficult to cool effectively, leading to inefficient cooling in existing systems.

Innovation Solution

A cooling device with a contra-rotating fan arrangement that produces a non-turbulent, parallel air stream, which is directed towards the braking device and/or power-generating means, providing a more efficient cooling effect by increasing air pressure and allowing precise targeting of the cooling stream, and can be regulated based on engine power levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a single fan system is used for cooling, then the device complexity is low, but the cooling effect is insufficient for high power engines

Engineering Contradiction:
Improvecooling effectVSAvoidfan arrangement complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines two fan systems into a single integrated cooling device with contra-rotating fans. The first and second fans are mounted on the same housing and share a common drive mechanism, merging their cooling functions while eliminating the need for separate drive systems. This combination achieves superior cooling performance (2-3 times greater than single fan systems) while controlling overall device complexity through shared components.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If contra-rotating fans are used to produce non-turbulent air stream, then the cooling efficiency increases, but the device complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidfan arrangement complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs dynamic contra-rotating fans that can rotate in opposite directions to actively manage airflow characteristics. The fans are driven by a variable speed drive mechanism that can adjust rotational speeds and directions based on cooling demands. This dynamic capability produces a non-turbulent parallel air stream that significantly improves cooling efficiency by directing airflow precisely where needed without excessive turbulence.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cooling device with contra-rotating fans serves multiple functions: it provides primary cooling for the engine radiator, secondary cooling for the power-absorbing means, and can simulate wind resistance for testing purposes. The same fan arrangement adapts to different operational requirements by adjusting fan speeds and directions, eliminating the need for separate cooling systems for different components.

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

3Temperature

If higher air pressure is generated for precise targeting of cooling stream, then the cooling effect improves, but the energy consumption increases

Engineering Contradiction:
Improvecooling effectVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The cooling system incorporates feedback control through a variable speed drive that responds to cooling demands. The control system monitors temperature conditions and adjusts the fan speeds accordingly, generating higher air pressure only when and where needed for precise targeting of the cooling stream. This feedback mechanism ensures high cooling effectiveness while minimizing energy consumption by avoiding unnecessary high-pressure operation during low-demand conditions.

Inventive Principle:
Principle #23Feedback

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 system achieves a 2-3 times greater cooling effect compared to single fan systems, efficiently directing airflow to power-absorbing and engine radiators, and can simulate wind resistance, effectively managing cooling demands even under high power conditions.

Implementation Method 1

the resulting air stream, as opposed to the rotating, turbulent air stream of a single fan system, constitutes a relatively non-turbulent, non-rotating parallel air stream

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

a heat exchanger for providing a cooling effect

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP1907814B1System and method for dynamometer testing of motor vehicles, including a cooling device
Publication Date: 2018.08.01 ROTOTEST INT
  • EP1907814B1 patent drawingFigure 1
  • EP1907814B1 patent drawingFigure 2
  • EP1907814B1 patent drawingFigure 3~4

AI summary

The present invention relates to a system for dynamometer testing of motor vehicles, said system including a cooling device for a braking device and/or a power-generating means, and having power-absorbing means for absorbing a power applied thereto by power-generating means, the cooling device including a fan arrangement for producing an air stream, said air stream being intended to be directed towards the braking device and/or the power-generating means and/or a heat exchanger for providing a cooling effect. The fan arrangement includes two fans, which are substantially axially aligned, and the cooling device includes means for rotating the fans in opposite directions relative to each other. The present invention also relates to a method for cooling power-generating means or power-absorbing means in a system for dynamometer testing of motor vehicles.