초록 ▼

A tri-element carbon based heat shield has an outer layer including a carbon-carbon composite, a middle layer including pyrolytic graphite deposited onto an inner surface of the outer layer and an inner layer including carbon felt or foam having low density and high mechanical compliance. The thickn

A tri-element carbon based heat shield has an outer layer including a carbon-carbon composite, a middle layer including pyrolytic graphite deposited onto an inner surface of the outer layer and an inner layer including carbon felt or foam having low density and high mechanical compliance. The thickness of each layer is selected for optimizing thermal protection over the expected operating temperature range. Although a carbon-carbon composite has a higher thermal diffusivity (inversely related to thermal insulation efficiency) than pyrolytic graphite, the carbon-carbon is selected as the outer layer in a minimum thickness sufficient to satisfy the structural strength, ablation and recession requirements of the heat shield. The resulting thickness of the outer layer determines the operating temperature range of the middle layer. At a predetermined temperature, the thermal diffusivity of the inner layer becomes less than that of the middle layer so that the thickness of the inner layer is selected to operate from this predetermined temperature to all lower temperatures.

대표청구항 ▼

A heat shield comprising: layer including a carbonaceous material, the outer layer having a first thermal diffusivity, an outer surface, an inner surface and a thickness disposed between the outer and inner surface, the outer surface for operating at a predetermined expected maximum temperature; a m

A heat shield comprising: layer including a carbonaceous material, the outer layer having a first thermal diffusivity, an outer surface, an inner surface and a thickness disposed between the outer and inner surface, the outer surface for operating at a predetermined expected maximum temperature; a middle layer including pyrolytic graphite, the middle layer deposited on the inner surface of the outer layer, the middle layer having a second thermal diffusivity, an inner surface and a thickness disposed between the inner surface of the outer layer and the inner surface of the middle layer; and an inner layer including a compliant material having an outer surface for abutting the inner surface of the middle layer, the inner layer having a third thermal diffusivity, an inner surface and a thickness disposed between the outer and inner surface, wherein the operational temperature at the inner surface of the inner layer is less than a protective limit temperature when the outer surface of the outer layer is at the predetermined expected maximum temperature. The heat shield as in claim 1, wherein the compliant material includes a carbon felt.