Hydrogen Nozzle Cap Flow Guidance to Reduce Vortices

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Solution Overview

Problem

Hydrogen nozzles in internal combustion engines face challenges in maintaining the direction of the jet, particularly at sonic or supersonic flows, leading to vortices and residual gases that can auto-ignite at unfavorable timings.

Innovation Solution

A nozzle cap with an internal bottom flow-guiding body and optionally a side flow-guiding body that redirects hydrogen flow towards the outlet, minimizing vortices and reducing residual gases by shaping the flow-guiding surfaces to ensure hydrogen stream directionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the nozzle cap hole exit area is made larger than conventional engine nozzles, then the hydrogen flow rate is improved, but the ability to direct the jet in a wanted direction deteriorates and disturbing vortices are generated

Engineering Contradiction:

Improvehydrogen flow rateVSAvoidjet direction control

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The nozzle cap is segmented into multiple functional zones: a flow-guiding body with a flow-guiding surface that divides the cap volume into a flow-guiding volume and a residual volume. This segmentation allows the large exit area to maintain high flow rate while the flow-guiding surface provides directional control and reduces vortices by organizing the flow pattern.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow-guiding surface acts as an intermediary element between the inlet and outlet. It mediates the hydrogen flow by redirecting it from the inlet toward the outlet in a controlled manner, preventing direct chaotic flow that would create vortices while maintaining the large exit area needed for high productivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the nozzle cap hole exit area is made larger than conventional engine nozzles, then the hydrogen flow rate is improved, but the cap volume contains residual hydrogen-containing gases that may auto-ignite at un-favourable timing

Engineering Contradiction:

Improvehydrogen flow rateVSAvoidignition timing control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The cap volume is segmented into a flow-guiding volume where active hydrogen flow occurs and a separate residual volume isolated by the flow-guiding body. This segmentation confines residual hydrogen-containing gases to a limited space away from the main flow path, reducing the risk of un-favourable auto-ignition while maintaining large exit area for high flow rate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow-guiding body extracts and isolates the residual hydrogen-containing gases from the main hydrogen flow path. By taking out the residual volume and separating it from the active flow zone, the design reduces the hazard of residual gases auto-igniting at un-favourable timing while preserving the large exit area needed for productivity.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If conventional nozzle cap designs are used, then the structure is simple, but disturbing vortices are generated that re-direct part of the flow in an un-favourable direction

Engineering Contradiction:

Improvenozzle cap structureVSAvoidflow direction control

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The nozzle cap is segmented into functional zones using a flow-guiding body that creates distinct flow-guiding and residual volumes. This segmentation introduces controlled complexity that enables effective flow direction control, reducing vortices and preventing un-favourable flow redirection while maintaining reasonable structural simplicity.

Inventive Principle:

Principle #1Segmentation

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 nozzle cap efficiently guides hydrogen flow to the outlet, reducing vortices and residual gases, thereby improving hydrogen injection efficiency and safety in internal combustion engines.

Implementation Method 1

The internal bottom flow-guiding body comprises a convex ridge protruding towards the inlet and comprises a flow-guiding surface for re-directing a flow of hydrogen from the inlet towards the outlet

Methodology Applied

Scientific EffectFluid flow guidance:

Data Source

PatentEP4374058B1A nozzle cap for a fuel injection nozzle operable in a hydrogen internal combustion engine

Publication Date: 2025.07.09 VOLVO TRUCK CORP

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Figure 2A~2B
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AI summary

The invention relates to a nozzle cap (100) for a fuel injection nozzle operable in a hydrogen internal combustion engine (2), the nozzle cap comprising an inlet (104) for receiving a flow of hydrogen controllable by an inlet valve (106) arrangeable in the inlet, at least one outlet (108) for providing an exit flow of hydrogen, and an internal bottom flow-guiding body (109) arranged at a bottom side (110) of the nozzle cap downstream of the inlet in a nozzle cap volume (111), the internal bottom flow-guiding body protruding towards the inlet and comprises a flow-guiding surface (112) for re-directing a flow of hydrogen from the inlet towards the outlet. The invention also relates to a fuel injection nozzle comprising an inlet valve and a nozzle cap, to a hydrogen internal combustion engine (2) comprising a fuel injection nozzle, and to a vehicle comprising such a fuel injection nozzle or such a hydrogen internal combustion engine.