Thermal Sensor Development and Testing for NASA Entry Probe Thermal Protection Systems

Empirical correlations have been widely used to map the penetration and trajectory of an injected liquid jet into a gaseous crossflow. Such correlations for the case of cryogenic liquid injection into a gaseous crossflow of the same species are limited. In this study, mediumresolution images of the injection of cryogenic liquid nitrogen into a gaseous nitrogen crossflow with momentum blowing ratios of 1-4 and Weber numbers of 1500-4500 are captured and image analysis is used to identify the jet boundary. Using these data, an empirical correlation for the penetration of liquid nitrogen into a gaseous crossflow as a function of momentum blowing ratio and downstream distance from the point of injection is developed. Minimizing the root mean square error of the correlation parameters over the full range of experimental conditions investigated leads to a power-law correlation with a mean error of 16%.

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“…The error in temperature measured using platinum resistance temperature detectors is 0.25C or 0.5% [23].…”

Section: Experimental Overviewmentioning

confidence: 95%

An Empirical Correlation for the Penetration of a Cryogenic Liquid Jet into a Gaseous Crossflow

Ravichandran

Kirk

2021

IREASE

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“…To combine the spatial and temporal responses of a heat flux sensor, only Eqs. 7and (8) are needed, as repeated here.…”

Section: Fig 3 Comparison Of Slug Calorimeter Response Using Differementioning

confidence: 99%

“…However, accurately measuring any two of these allows the third to be calculated since ΔT=T 1 -T 2 . For the two sensors already mentioned [8,9] this will not require any change in design as these sensors already measure the required temperatures. Also, none of the aforementioned analysis placed any requirements on which temperatures were used in evaluating the slug calorimeter term.…”

Section: Fig 3 Comparison Of Slug Calorimeter Response Using Differementioning

confidence: 99%

A Hybrid Method for Measuring Heat Flux

Hubble

Diller

2009

Journal of Heat Transfer

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The development and evaluation of a novel hybrid method for obtaining heat flux measurements is presented. By combining the spatial and temporal temperature measurements of a heat flux sensor, the time response, accuracy, and versatility of the sensor is improved. Sensors utilizing the hybrid method are able to make heat flux measurements on both high and low conductivity materials. It is shown that changing the thermal conductivity of the backing material four orders of magnitude causes only an 11% change in sensor response. The hybrid method also increases the time response of heat flux sensors. The temporal response is shown to increase by up to a factor of 28 compared with a standard spatial sensor. The hybrid method is tested both numerically and experimentally on both high and low conductivity materials and demonstrates significant improvement compared with operating the sensor as a spatial or temporal sensor alone.

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Thermal Sensor Development and Testing for NASA Entry Probe Thermal Protection Systems

Cited by 2 publications

References 0 publications

An Empirical Correlation for the Penetration of a Cryogenic Liquid Jet into a Gaseous Crossflow

An Empirical Correlation for the Penetration of a Cryogenic Liquid Jet into a Gaseous Crossflow

A Hybrid Method for Measuring Heat Flux

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