Comparative Surface Heat Transfer Measurements in Hypervelocity Flow

Flaherty, William; Austin, Joanna

doi:10.2514/1.50450

Cited by 34 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The good agreement between experimental and analytical temperature history is evident. This temperature behavior is analogous to the one reported for heat transfer measurements in a shock tunnel where heat flux gets applied as a step load [7,13,16]. Parabolic behavior of temperature-time history confirms the constancy of the applied heat load.…”

Section: Transient Temperature Historysupporting

confidence: 79%

“…These gauges can measure the temperature difference across the insulating layer but the main disadvantage of such gauges is difficulty in its fabrication. Many techniques are available for making the thin films such as vacuum coating, sputtering or hand painting with the help of sophisticated brush [7,[15][16][17]. In general, thickness of the thin film is kept up to few micrometers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multi-walled carbon nano-tubes for performance enhancement of thin film heat flux sensors

2019

View full text Add to dashboard Cite

Surface heat transfer measurement is an important aspect in many research problems. Thin film heat flux sensor (TFHFS) is mostly considered in such situations for heat flux measurement due to its quick response and high accuracy. In the present studies, multi-walled carbon nanotubes (MWCNTs) are mixed with platinum while making the TFHFSs. Such addition is noticed to increase the sensitivity and decrease the temperature coefficient of resistance (TCR) of the thin film sensors. Improved sensitivity by 151% and 119% for Macor and Quartz sensors has led to increase in strength of the temperature response of the sensors during dynamic calibration experiments. Though heat flux recovery is seen to have encouraging agreement for all the sensors, sensitivity enhancement is noticed to be more prominent and advantageous for Macor based sensors. Present studies recommend adequately finished substrate for better adhesion. Further, use of MWCNTs is advisable especially for low heat flux measurement and also for Macor substrate since either situation demands the higher sensitivity to increase the output response.

show abstract

Section: Transient Temperature Historysupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Multi-walled carbon nano-tubes for performance enhancement of thin film heat flux sensors

2019

View full text Add to dashboard Cite

show abstract

“…Because of its rigorous theoretical basis as well as simplicity, F–R has been extensively used as a reference value for hypersonic aerothermal heating (Zuppardi and Verde, 1998), not only for numerical estimation of the reentry flight (Park and Balakrishnan, 1985; Yamamoto and Yoshioka, 1995; Park et al , 1998; Cheatwood et al , 2001; Park, 2001; Papadopoulos and Subrahmanyam, 2005; Cassell et al , 2011) but also for flow-field characterization in hypersonic ground test facilities (Olivier, 1993; Chadwick, 1997; Carlson, 1999; Kuchi-ishi et al , 2003; Marineau and Hornung, 2009; Saravanan et al , 2009; Schrijer and Bannink, 2010; Flaherty and Austin, 2011; Srinivasan et al , 2016; Bensassi et al , 2017; Saiprakash et al , 2019).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Fay and Riddell formula under hypersonic flight conditions

Lee

Yang

Kim

2022

HFF

View full text Add to dashboard Cite

Purpose The Fay and Riddell (F–R) formula is an empirical equation for estimating the stagnation-point heat flux on noncatalytic and fully catalytic surfaces, based on an assumption of equilibrium. Because of its simplicity, the F–R has been used extensively for reentry flight design as well as ground test facility applications. This study aims to investigate the uncertainties of the F-R formula by considering velocity gradient, chemical species at the boundary layer edge, and the thermochemical nonequilibrium (NEQ) behind the shock layer under various hypersonic NEQ flow environments. Design/methodology/approach The stagnation-point heat flux calculated with the F–R formula was evaluated by comparison with thermochemical NEQ calculations and existing flight experimental values. Findings The comparisons showed that the F–R underestimated the noncatalytic heat flux, because of the chemical composition at the surface. However, for fully catalytic heat flux, the F–R results were similar to values of surface heat flux from thermochemical NEQ calculations, because the F–R formula overestimates the diffusive heat flux. When compared with the surface heat flux results obtained from flight experimental data, the F–R overestimated the fully catalytic heat flux. The error was 50% at most. Originality/value The results provided guidelines for the F–R calculations under hypersonic flight conditions and for determining the approximate error range for noncatalytic and fully catalytic surfaces.

show abstract

“…Thin-film heat transfer gauges which are commonly used in low enthalpy testing only survive one shot when mounted on blunt body geometry in high enthalpy facilities [5,6]. Surface junction thermocouples [7][8][9][10] are very robust but often require re-abrading or re-machining between shots due to damage from the flow.…”

Section: Introductionmentioning

confidence: 99%