New High Quality Diesel Nozzle DSLA156P1412 0 433 175 417 for Injection Nozzle Diesel Engine Parts

Abstract

Turbocharged gasoline and diesel engines require fuel injectors capable of rapid, precise fuel delivery under highly dynamic pressure and load changes. The high-speed response characteristics of injector nozzles directly influence mixture formation, combustion efficiency, turbocharger boost stability, and emission performance. This research investigates the structural, hydraulic, and electromagnetic factors affecting injector response time and proposes an optimized nozzle design with improved dynamic response. Simulation and bench-test results show that the new design reduces opening delay by up to 18% and improves fuel delivery accuracy under transient conditions.

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1. Introduction

Turbocharged engines operate under rapidly fluctuating intake pressure, increased cylinder temperature, and elevated rail pressure. These conditions require injectors to respond quickly to ECU commands while delivering fuel with high precision and repeatability. Conventional nozzle designs often suffer from:

• Slow needle lift response

• Insufficient dynamic flow rate

• Delayed spray development under high boost

• Sensitivity to pressure pulsation

This paper focuses on analyzing the limitations of conventional injector nozzles and designing a high-speed response nozzle specifically for turbocharged engine application.

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2. High-Speed Response Requirements in Turbocharged Engines

2.1 Rapid Airflow and Pressure Dynamics

Turbochargers significantly accelerate cylinder filling. As a result, injectors must adjust fuel delivery within milliseconds to maintain:

• Correct air–fuel ratio under boost

• Avoidance of lean surges

• Prevention of knock or over-fueling

2.2 Increased Rail Pressure

Modern turbocharged engines operate with rail pressures of:

• Gasoline DI: 200–350 bar

• Diesel CR: 1600–2500 bar

Higher pressure increases the demand for:

• Faster needle opening

• Stronger sealing

• Stable spray atomization

2.3 Multi-Injection Strategies

Fast response is required to support:

• Pilot injection

• Main injection

• Post injection

• Split injection for NOx and PM reduction

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3. Methodology

3.1 Modeling Tools

• 3D CFD simulation (spray, cavitation, transient flow)

• FEM analysis for needle dynamics

• Electromagnetic coil simulation for solenoid injectors

3.2 Test Bench Setup

An advanced injector test bench was utilized, capable of:

• 2500 bar rail pressure

• 0.1 ms response measurement

• High-speed imaging of spray patterns

• Transient injection flow assessment

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4. Key Factors Affecting High-Speed Response

4.1 Needle Mass and Inertia

Lower needle mass reduces:

• Opening delay (td)

• Closing delay (tc)

• Total injection duration

Optimized needle geometry is essential.

4.2 Hydraulic Force and Flow Resistance

Nozzle flow path should minimize:

• Pressure drop

• Cavitation losses

• Fuel turbulence

Sharper edge design and smoother transitions improve response.

4.3 Solenoid/Electromagnetic Actuation

Response time is influenced by:

• Coil inductance

• Magnetic flux density

• Residual magnetism

• Air gap shape

A strong, fast magnetic circuit improves needle lift speed.

4.4 Multi-Hole Nozzle Geometry

Turbocharged engines often require:

• Higher flow rate

• Wider spray angles

• Strong penetration under boost

Hole diameter, number, and direction must be refined.

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5. Proposed High-Speed Response Nozzle Design

5.1 Lightweight Needle Design

• Reduced mass by 12–15%

• Use of high-strength, thin-wall structure

• Low-friction DLC coating to reduce drag

5.2 Optimized Multi-Hole Spray Design

• 6–8 micro-holes (120–160 μm)

• Enhanced hole inlet rounding (R=0.02–0.04 mm)

• Improved cavitation control for faster atomization

5.3 High-Force Electromagnetic Actuation

• Shortened air gap

• Optimized coil winding pattern

• Faster magnetic flux buildup

Results: 0.08–0.12 ms faster needle opening

5.4 Hydraulic Flow Path Adjustment

• Enlarged needle seat cone angle

• Reduced vortex formation zones

• Shorter fuel path for quicker pressure buildup

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6. Experimental Results

6.1 Opening and Closing Delay

6.2 Flow Rate Stability

At 2000 bar rail pressure:

• Injection quantity variation reduced from 2.9% → 1.8%

• Better consistency under rapid boost transitions

6.3 Spray Development

High-speed imaging showed:

• Faster spray formation

• 11% reduction in SMD (better atomization)

• Stronger penetration despite turbulence from turbo boost

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7. Discussion

The improved nozzle design effectively meets the high responsiveness required for turbocharged engines. Faster needle dynamics allow better control of multi-stage injection, and the optimized spray pattern supports efficient combustion even under high boost pressure.

The combination of structural, hydraulic, and electromagnetic improvements proves essential in achieving the desired high-speed characteristics.

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8. Conclusion

The study demonstrates that high-speed response of injector nozzles can be significantly improved through:

1. Lightweight, low-inertia needle design

2. Refined multi-hole geometry

3. Enhanced electromagnetic actuation

4. Optimized hydraulic flow path

The resulting injector design meets the demanding requirements of turbocharged engines, offering improvements in acceleration response, fuel efficiency, and emissions control.

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9. Future Work

Further research will explore:

• Piezoelectric actuators for ultra-fast response

• Real-time spray adjustment under varying boost pressures

• AI-based injector control strategies

• Additive-manufactured micro-hole nozzles