Peak temperature attenuation film
A heat transfer system comprises a substrate and a thin film coating in physical and thermal contact with the substrate at an interface. The substrate is configured to transmit thermal waves, and has a first effusivity and a first thickness. The thin film coating has a second effusivity less than the first effusivity, and a second thickness less than the first thickness.
1. A peak temperature attenuation system comprising:
a dielectric layer of a capacitor;
a substrate forming an electrode of the capacitor, and configured to transmit thermal waves, the substrate having a substrate thermal effusivity and a substrate thickness; and
a thin film coating disposed between the substrate and the dielectric layer, in physical and thermal contact with the substrate at an interface, the thin film coating having a film thermal effusivity less that the substrate thermal effusivity, and a substantially uniform film thickness on the order of a thermal wavelength of the thermal waves and less than the substrate thickness;
wherein the capacitor discharges power to a resistive heater of an ice protection system.
2. The peak temperature attenuation system of claim 1 , wherein the substrate is configured to produce the thermal waves via self-heating.
3. The peak temperature attenuation system of claim 1 , wherein the substrate thickness is at least 400 times the film thickness.
4. The peak temperature attenuation system of claim 1 , wherein the substrate and the thin film coating are bonded at the interface via molecular bonding with substantially no contamination.
5. The peak temperature attenuation system of claim 1 , wherein the substrate is formed a material selected from the group consisting of copper, nickel, aluminum, titanium, and alloys of copper, nickel, aluminum, titanium, and combinations thereof.
6. The peak temperature attenuation system of claim 1 , wherein the thin film coating is formed of an electrically conductive material.
7. The peak temperature attenuation system of claim 6 , wherein the electrically conductive material is selected from the group consisting of copper, silver, and nickel.
8. The peak temperature attenuation system of claim 1 , wherein the substrate thermal effusivity is at least twice the film thermal effusivity.
9. A method of reducing peak temperatures in an electrode substrate of a capacitor due to transient thermal waves using a peak temperature attenuation system, comprising:
a dielectric layer of a capacitor;
a substrate forming an electrode of the capacitor, and configured to transmit thermal waves, the substrate having a substrate thermal effusivity and a substrate thickness; and
a thin film coating disposed between the substrate and the dielectric layer, in physical and thermal contact with the substrate at an interface, the thin film coating having a film thermal effusivity less that the substrate thermal effusivity, and a substantially uniform film thickness on the order of a thermal wavelength of the thermal waves and less than the substrate thickness;
wherein the capacitor discharges power to a resistive heater of an ice protection system,
the method comprising:
applying the thin film coating in physical and thermal contact with the electrically conductive substrate, between the substrate and the dielectric layer of the capacitor, at the interface such that reflections of the transient thermal waves across the interface interfere destructively with the transient thermal waves.
10. The method of claim 9 , wherein applying the thin film coating comprises depositing the coating via physical vapor deposition.
11. The method of claim 9 , wherein the electrically conductive substrate thermal effusivity is at least twice the film thermal effusivity.