Rocket engine hot-spot detector
Abstract
On high performance devices such as rocket engines it is desirable to know if local hot spots or areas of reduced cooling margin exist. The objective of this program is to design, fabricate and test an electronic hot spot detector capable of sensing local hot spot on the exterior circumference of a regeneratively cooled combustion chamber in order to avoid hardware damage. The electronic hot spot sensor consists of an array of 120 thermocouple elements which are bonded in a flexible belt of polyimide film. The design temperature range is from +30 F to +400 F continuously with an intermittent temperature of 500 F maximum. The thermocouple belt consists of 120 equally spaced copper-Constantan thermocouple junctions which is wrapped around the OMS liquid rocket engine combustion chamber, to monitor temperatures of individual cooling channels. Each thermocouple is located over a cooling channel near the injector end of the combustion chamber. The thermocouple array sensor is held in place by a spring loaded clamp band. Analyses show that in the event of a blocked cooling channel the surface temperature of the chamber over the blocked channel will rise from a normal operating temperature of approx. 300 F to approx. 600 F. The hot spot detector will respond quickly to this change with a response time constant less than 0.05 seconds. The hot spot sensor assembly is fabricated with a laminated construction of layers of Kapton film and an outer protective layer of fiberglass reinforced silicone rubber.
- Publication:
-
Final Report Aerojet TechSystems Co
- Pub Date:
- April 1985
- Bibcode:
- 1985atc..rept.....C
- Keywords:
-
- Combustion Chambers;
- Combustion Products;
- Coolants;
- Damage;
- Detection;
- Electronic Equipment;
- Heat Flux;
- Hot Corrosion;
- Hot Surfaces;
- Liquid Propellant Rocket Engines;
- Loss Of Coolant;
- Regenerative Cooling;
- Thermocouples;
- Glass Fibers;
- Kapton (Trademark);
- Polyimides;
- Polymeric Films;
- Silicone Rubber;
- Instrumentation and Photography