Piston Cooling Channel Funnel Geometry for High-Speed Fluid Capture

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Solution Overview

Problem

At high piston speeds, the ingress efficiency of the cooling fluid into the piston's inner cooling channel is significantly reduced, leading to insufficient cooling of the piston.

Innovation Solution

The piston design includes an inlet channel with a rejuvenated flow cross-section, such as a funnel-shaped section, and optionally features surface treatments, coatings, or flow guidance elements to enhance cooling fluid flow and reduce friction losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the piston speed is increased to improve productivity, then the cooling fluid capture efficiency at the inlet decreases significantly, leading to insufficient piston cooling

Engineering Contradiction:
Improvepiston speedVSAvoidcooling fluid capture efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The inlet channel is designed with a funnel-shaped geometry featuring curved surfaces that transition from a larger inlet opening to a smaller outlet opening. This curved geometry effectively directs and captures the cooling fluid jet, increasing the proportion of cooling fluid that enters the piston cooling channel even at high piston speeds

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The inlet channel geometry is optimized by changing parameters such as the funnel angle, inlet opening size, and channel curvature. These parameter adjustments enable the inlet channel to maintain effective cooling fluid capture across a range of piston speeds, particularly improving performance at high speeds

Inventive Principle:
Principle #35Parameter changes

2Speed

If the inlet channel cross-section is reduced to increase cooling fluid velocity, then the cooling fluid flow rate may decrease, reducing cooling effectiveness

Engineering Contradiction:
Improvecooling fluid velocityVSAvoidcooling fluid flow rate
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The funnel-shaped inlet channel with its curved geometry smoothly transitions the cooling fluid from a larger inlet opening to a smaller outlet opening. This curved design maintains fluid momentum and reduces turbulence, enabling high velocity while preserving adequate flow rate

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The inlet channel is designed to rapidly accelerate the cooling fluid through its length, allowing the fluid to 'rush through' the channel at high velocity. This ensures that the cooling fluid reaches the piston cooling channel inlet with sufficient speed and kinetic energy to maintain effective cooling

Inventive Principle:
Principle #21Skipping (Rushing through)

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 design ensures sufficient cooling of the piston even at high speeds by intensifying the entry of cooling fluid into the piston cooling channel, reducing temperature, and minimizing cooling fluid loss.

Implementation Method 1

The inlet channel (16) is designed in a funnel shape at least partially in one direction towards the inlet (28) of the internal piston cooling channel (20)

Methodology Applied
Scientific EffectFunnel shape flow direction: Funnel

Implementation Method 2

the inlet channel (16) has means (e.g. surface treatment, coating and/or flow control element(s)) to promote a cooling fluid flow to the piston cooling channel

Methodology Applied
Scientific EffectSurface treatment:

Data Source

PatentEP3508714B2Piston for a combustion engine
Publication Date: 2025.04.02 MAN TRUCK & BUS SE
  • EP3508714B2 patent drawingFigure 1~3
  • EP3508714B2 patent drawingFigure 4~5
  • EP3508714B2 patent drawingFigure 6~7

AI summary

The invention relates to a piston (10) for an internal combustion engine. The piston (10) has an internal piston cooling channel (20) for cooling the piston (10). The piston (10) has an inlet channel (16) that opens into an inlet (28) of the piston cooling channel (20), wherein a flow cross-section of the inlet channel (16) tapers at least partially, in particular in a funnel shape, in one direction towards the inlet (28) of the internal piston cooling channel (20), and the inlet channel (16) is additionally designed to convey a flow of cooling fluid to the inlet (28) of the internal piston cooling channel (20). The invention makes it possible to ensure sufficient cooling of the piston (10) even at high piston speeds.