NEWS - HEAT EXCHANGE / HEATSINK :
01/09/2013

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Your thermal application and metal foam

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Metal foam are produced by the Cast Foam® casting process, therefore we can adapt size and shape of the metal foam to your specific needs and applications, such as thermal management.

Metal foam technology and heat dissipation by natural convection

If you dissipate heat by natural convection, you may confront several issues such as pressure losses and heat transfer surface. For these applications, metal foams bring innovative and efficient solutions.

Generally the bulk density is function of temperature and additional Celsius degree implies a difference of density. This difference of density implies a difference of Archimedes’ principle therefore it creates a movement called convection movement. These convection movements are generally slow; consequently they are affected by pressure losses.

Heat dissipater made in metal foam with big cells improves fluid flow by minimizing pressure losses. Moreover effect of boundary layer is reduced because our metal foam has a regular shape.

For our customers, we have already realized studies about heat dissipation by natural convection. Therefore we have demonstrated that thanks to metal foam technology, size of the heat sink is divided by two without reducing performances.

For each particular need, we can also adapt metal foam design in order to always maximize speed of flows through the radiator and improve heat dissipation.

 

Metal foam technology and heat dissipation by forced convection, oil heat exchangers

When we use oil in heat exchange system, the main issue concerns the fact that viscosity of oil depends on temperature. If oil is colder, it is more viscous, consequently boundary layers become important and heat dissipater is not optimized.

Using metal foam technology improved oil mixing inside the radiator, thanks to its 3D structure. Thus, oil is continuously mixed, its temperature is homogeneous, boundary layer is lower and it improves thermal performances.

Metal foam and energy storage

In numerous cases, it could be useful to store energy in order to use it after.

There are two main types of heat storage technology:

  • Storage by sensible heat technology: energy is stored by increasing temperature of a material. Quantity of stored energy is therefore strictly proportional to volume, increasing of temperature and material’s thermal capacity.
  • Storage by latent heat technology:  energy is stored by changing (melting or vaporization) the material. Quantity of stored energy depends on latent heat and quantity of material.

In these two types of solutions, material’s thermal conductivity is low for cost reasons in the first solution or physical reasons in the second solution (losses for each change) This low conductivity rate limits storage capacity. However, metal foam technology can increase thermal conductivity and thus increase storage capacity.