Development of an Experimental Apparatus for Ablative Nanocomposites Testing

Eric Allcorn, Sam Robinson, David Tschoepe, Joseph Koo, Maurizio Natali
2011 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit   unpublished
This study involves the design of a small scale apparatus to test ablative materials, which are commonly used to provide thermal protection to key structural components of solid rocket motors (SRMs). The testing of these materials involves subjecting them to extreme heat and fluid velocities while measuring the resulting temperature on various points of the sample. Observation of the front and back face temperatures during testing, as well as post test analysis of material erosion and mass
more » ... osion and mass loss, can provide a quick assessment of the efficacy of newly developed ablative materials. The setup developed through this project is designed to be a small-scale device with quantified heat input and temperature values for the testing of ablatives such as carbon/phenolic composites, C/C composites, conventional polymer composites, and polymer nanocomposites. This device will perform tests on small samples of ablative materials with a front face of roughly 12.7 x 12.7mm (0.5 x 0.5 in.) and 15-50mm thickness. A high temperature flame produced through the use of an oxyacetylene torch system will be directed and focused on this small sample face through the use of a welding nozzle, which will accelerate the flame towards the sample at high velocity. Prior to testing and in order to properly quantify the heat flux generated by this device, a slug calorimeter is used to calibrate the flame by measuring the rate of change of temperature for a slug of material at different distances from the nozzle exit. Data is gathered during testing through the use of multiple thermocouples to measure the back face and/or heat soak temperatures of the sample. These readings are obtained using a data acquisition (DAQ) card and recorded over time using a LabView VI. Due to a specific procedure required to light the oxyacetylene torch, the testing method for this device involves first lighting the torch and adjusting it to the proper fuel ratio, then moving the torch along a single axis slide up to the specified testing distance (used to determine input flux). The data of initial material testing with this apparatus are compared to knowledge of the materials tested, as well as data from tests with a similar apparatus to determine the overall validity of the results gathered from the developed apparatus.
doi:10.2514/6.2011-6050 fatcat:pyykv455urcxvfmabs2d3sz2qu