Combustion

Combustion research is found in a variety of industries and can require advanced imaging techniques. A common automotive application is the activation of engine pistons. Explosives combustion is extremely fast and can be applied to everything from a firecracker to dynamite. Aerospace research includes rocket combustion such as hot exhaust and thrust creation, and supersonic combustion, when airflow moves beyond the speed of sound. Advanced study of these events can advance research on destructive capabilities, power efficiency, and waste reduction.

High-speed imaging gives research scientists a close look into:

  • Complete stoichiometric combustion
  • Incomplete combustion and byproduct creation
  • Shock waves formation in air, water, and solids
  • Fuel spray dynamics critical in the moments before combustion
  • Transparent flows that indicate heat, air pressure, and airflow generation

Understanding Combustion and Research Goals

When imaging combustion it is important that two key points are considered so the proper advanced imaging technique will be used to acquire the proper data.  Most importantly is that the researchers need to define what the specific goals are for the study. Without understanding the research goals the high-speed combustion imaging can become a difficult and expensive undertaking.  The secondary point is to understand which part of the combustion action needs to be imaged to obtain the proper data.  Combustion events have five critical parts: 

  • Mechanical Engineering of Valves and Timing – Vibration and other events affecting reliability
  • Chemical Engineering During Active Combustion – Wavelength emissions of flame
  • Fluid Dynamics Injection and Atomization – Qualifying droplet characteristics
  • Fluid Dynamics Under Compression – Study of burn efficiency
  • Chemical & Fluid Dynamics in Combustion Qualification – Characterization of flame shape

Challenges & Solutions

Combustion imaging has a unique set of challenges that come with extreme high-speed imaging. Each of these difficulties can be resolved by ensuring that both the correct tool (Phantom camera) and correct imaging techniques are used to produce accurate and clear high-speed imaging. Three of the most common are speed, light, and non-visible reactions.

Challenge 1: Extreme Speeds – Because combustion is a chemical reaction that occurs very quickly a minimum of 100,000 fps is required to adequately image the extremely fast movement. The Phantom TMX is a full 1 Mpx camera that can reach up to 1.75M fps.

Challenge 2: Bright Light – Intense light is a common energy output at the moment of combustion. High-speed sensors are light-sensitive and often oversaturation is a concern that can be solved through multi-camera setups, low exposure times, and the EDR (Extreme Dynamic Range) feature. 

Challenge 3: Non-visible Reactions – These types of reactions involve air and heat movement. They are not easily visible and require unique imaging methods, such as Schlieren, to ensure accurate and visible imaging data. 
Regardless of which challenge a research team is faced with Phantom camera experts are available to help ensure that the best techniques are being used to gather accurate and reliable data. 

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