Comparison of Coupled Radiative Flow Solutions with Project Fire 2 Flight Data

A nonequilibrium, axisymmetric, Navier-Stokes flow solver with coupled radiation has been developed for use in the design or thermal protection systems for vehicles where radiation effects are important. The present method has been compared with an existing now and radiation solver and with the Project Fire 2 experimental data. Good agreement has been obtained over the entire Fire 2 trajectory with the experimentally determined values of the stagnation radiation intensity in the 0.2-6.2 eV range and with the total stagnation heating. The effects of a number of flow models are examined to determine which combination of physical models produces the best agreement with the experimental data. These models include radiation coupling, multitemperature thermal models, and finite rate chemistry. Finally, the computational efficiency of the present model is evaluated. The radiation properties model developed for this study is shown to offer significant computational savings compared to existing codes

Spectroscopic Measurements in the Shock Relaxation Region of a Hypervelocity Mach Reflection

We examine the spatial temperature profile in the non-equilibrium relaxation region behind a stationary shock wave. The normal shock wave is established through a Mach reflection configuration from an opposing wedge arrangement for a hypervelocity air Mach 7.42 freestream. Schlieren images confirm that the shock configuration is steady and the location is repeatable. Emission spectroscopy is used to identify dissociated species and to obtain vibrational temperature measurements using the NO and OH A-X band sequences. Temperature measurements are presented at selected locations behind the normal shock. LIFBASE is used as the simulation spectrum software for OH temperature-fitting, however the need to access higher vibrational and rotational levels for NO leads to the use of an in-house developed algorithm. For NO, results demonstrate the contribution of higher vibrational and rotational levels to the spectra at the conditions of this study. Very good agreement is achieved between the experimentally measured NO vibrational temperatures and calculations performed using a state-resolved, one-dimensional forced harmonic oscillator thermochemical model

Transition Within a Hypervelocity Boundary Layer on a 5-Degree Half-Angle Cone in Air/CO_2 Mixtures

Laminar to turbulent transition on a smooth 5-degree half angle cone at zero angle of attack is investigated computationally and experimentally in hypervelocity flows of air, carbon dioxide, and a mixture of 50% air and carbon dioxide by mass. Transition N factors above 10 are observed for air flows. At comparable reservoir enthalpy and pressure, flows containing carbon dioxide are found to transition up to 30% further downstream on the cone than flows in pure air in terms of x-displacement, and up to 38% and 140%, respectively, in terms of the Reynolds numbers calculated at edge and reference conditions

Simulation of Ablating Hypersonic Vehicles with Finite-Rate Surface Chemistry

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140434/1/6.2014-2124.pd

Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals

This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2 The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio

The PACT Study: results of a time series study investigating the impact, acceptability and cost of an integrated model for psychosocial screening, care and treatment of patients with urological and head and neck cancers

Background: The significant psychosocial morbidity experienced by cancer patients is often undetected and untreated. Despite international priority given to psychosocial care for cancer patients, implementation of psychosocial programs into routine cancer care is limited. We developed, implemented, and assessed the impact, acceptability, and cost of an integrated, patient-centered Psychosocial Assessment, Care and Treatment (PACT) model of care for cancer patients within a general hospital setting. Methods: A time series research design was implemented to test the PACT model of care, newly introduced in an Australian tertiary hospital. System-level impact on systematic distress screening and management was assessed through audit of the medical records of three cross-sectional samples of 141 patients, at baseline and at 12 and 24 months post-baseline. The impact of the model on patient experience and health care professionals’ (HCPs) knowledge and confidence was assessed via surveys. The acceptability of the intervention was assessed through HCP interviews at 24 months. The cost of the intervention was assessed by PACT staff recording the time spent on care provision, training, and intervention administration, and associated costs were calculated using staff payment rates adjusted for superannuation and leave. Results: Across the 24 months of implementation, formal distress screening increased from 0% at baseline to 29% of patients at 12 months and 31% of patients at 24 months, with an associated decrease in informal screening as formal screening increased. There was no notable change in distress management (ie, development of care plans) across the time period. Baseline patient experience was already high (mean score = 46.85/55) and did not change significantly over the course of the study. In both general and specific areas of addressing patient psychosocial concerns, HCP knowledge and confidence was moderate and remained largely unchanged over the course of the study. HCPs perceived the PACT model as highly beneficial and instrumental in bringing about significant changes to staff's knowledge, practices and awareness of psychosocial issues. The estimated total labor cost (including on-costs) was AUD$119,239 (over the 2 years); with a declining cost over the lifetime of the intervention reflecting the higher initial set-up costs. Conclusions: Although the PACT model was associated with an increase in distress screening, staff workloads, high turnover, and administrative barriers may have restricted the translation into distress management. Future research exploring effective avenues to engage staff at a management level and ensure that staff view distress management as a valuable component of their role may assist to embed strategies into the general hospital culture and lead to more sustainable changes