Torpedo Igniter Coating and Control for Corrosive Starts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torpedo propulsion systems face challenges in efficiently igniting combustible materials within a combustion chamber, particularly in corrosive environments, and ensuring reliable operation across varying battery states and temperatures.
Innovation Solution
A hybrid electric torpedo system with a controller that manages battery state and resistance to control the igniter and fuel pump, using a unitary ignition element with an Inconel hermetic coating to ensure reliable ignition and fuel delivery, even in corrosive conditions, and a fuel pump with adjustable wobble angle for precise fuel flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional igniter system is used in torpedo propulsion, then the ignition function is provided, but the system lacks reliability in corrosive environments and across varying battery states
Solution Approach 1:
The patent applies composite materials by coating the ignition element with Inconel, a nickel-chromium alloy known for its corrosion resistance. This composite structure combines the igniter's functional material with a protective Inconel coating layer, creating a composite component that maintains ignition functionality while resisting corrosion from the harsh torpedo environment.
Solution Approach 2:
The patent implements a disposable igniter design where the ignition element is replaced after a single use or limited service life. This approach ensures that each igniter operates at peak performance without degradation from previous uses, maintaining reliable ignition while the corrosive environment would otherwise degrade reusable components.
2Reliability
If the igniter resistance is not monitored, then the system structure is simpler, but the ignition may fail due to open circuit conditions
Solution Approach 1:
The patent implements feedback by having the controller continuously monitor the resistance of the ignition element through the contactor circuit. When the resistance exceeds a predetermined threshold indicating an open circuit or degradation, the controller receives feedback and responds by preventing further ignition attempts, thereby maintaining system reliability through active monitoring.
Solution Approach 2:
The ignition system performs self-diagnosis by monitoring its own resistance characteristics. The controller automatically detects ignition element failures through resistance measurements without requiring external inspection, enabling the system to self-identify and respond to degradation conditions.
3Productivity
If fuel is delivered at all battery states, then fuel delivery is continuous, but energy is wasted when battery charge is insufficient
Solution Approach 1:
The patent applies dynamics by making the fuel pump operation conditional rather than continuous. The controller dynamically adjusts fuel pump activation based on real-time battery state of charge levels, enabling fuel delivery only when sufficient electrical energy is available to support both the pump operation and the high-current ignition discharge, thereby optimizing energy utilization.
Solution Approach 2:
The system changes the operational parameter of fuel delivery based on battery state of charge. When battery charge falls below a predetermined threshold, the controller modifies the fuel delivery parameter by preventing pump operation, thereby adapting the system's fuel delivery behavior to match available energy resources and avoid wasteful consumption.
4Reliability
If the contactor is not protected, then the device structure is simpler, but the contactor may weld due to high current and heat
Solution Approach 1:
The patent implements periodic action through duty cycle control of the contactor. The controller limits the contactor's operation to brief, periodic intervals during which ignition current is discharged, followed by cooling periods where the contactor is de-energized. This periodic on-off operation allows the contactor to dissipate heat between cycles, preventing welding while maintaining ignition functionality.
Solution Approach 2:
The controller performs preliminary action by monitoring and controlling contactor operation before thermal damage can occur. By anticipating the thermal buildup from repeated high-current cycles, the controller proactively limits contactor duty cycle and manages operation timing to prevent welding conditions from developing in the first place.
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
Ensures reliable ignition and efficient fuel delivery, maintaining propulsion system functionality across varying battery states and temperatures, enhancing operational reliability and efficiency.
Implementation Method 1
operate the contactor to conduct current through the igniter such that a temperature of the igniter increases
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a hybrid electric torpedo comprising: a combustion chamber (130) defining an aperture; and an igniter (138) having a resistance, a current source, and a contactor. The igniter includes a housing having terminals configured to receive electrical conductors, and a unitary ignition element (134) having ends conductively joined with the terminals and having an ignition element material composition, the igniter including an Inconel hermetic coating that encapsulates the unitary ignition element and including an Inconel hermetic seal formed to join the aperture.