An Investigation of the Dynamic Response of Thermocouples in Inert and Reacting Condensed Phase Energetic Materials

Abstract

Thermocouples are widely used to measure both transient and steady state temperatures in many different materials. Bead diameters range from a few micrometers to several millimeters. During steady state operations, dynamic response is not an issue. However, during fluctuating conditions, the temporal response of the thermocouple must be taken into account. Several different techniques have been developed to measure the response characteristics of measurements in inert gases and liquids, but to the authors knowledge, relatively little work has been conducted in condensed phase reacting materials. This report presents an initial survey of the topic.

Application of the spherical metric tensor to grid adaptation and the solution of applied problems

“…The Beltrami equations in (6) in metric (15) have the form (16) where . The inverted Beltrami equations in metric tensor (15) are written as (17) where (18) Diffusion equations (8) in metric (15) are given by (19) Therefore, in this metric, the inverted diffusion equations required for adaptive grid generation in have the form…”

“…Grounded thermocouple sensors find wide applications in various engineering devices used to measure heat fluxes in complex heat stressed structures [14], various heat exchange devices [15], and in the burn ing of unitary solid fuel [16][17][18]. In this case, the problem arises of estimating the reliability of quantities derived from thermocouple measurements.…”

Cookoff

“…Laser heating measurements of these thermocouples in air and in water give a response time of between 1.5 and 10 ms depending on the thermal conductivity of the surrounding medium [33,34]. This range is used to deconvolve the temperature measurements in the ignition volume and back out actual HE temperatures.…”

The error of temperature measurement by a thermocouple in a burning unitary solid propellant

“…Conclusions (1) Numerical simulation has revealed the presence of a considerable error in temperature measurement in SP with the use of a thermocouple. The magnitude of this error depends both on the burning rate and the size of the thermocouple junction.…”

“…Unfortunately, this fact was not properly attended for a long time and the error estimates for temperature measurements by thermocouples are quite contradictory. There are just a few studies [1][2][3] considering this problem. Therefore, in this paper we study the indicated heat exchange processes with the use of numerical simulation and give estimates of possible errors in temperature measurement in SP by thermocouples.…”