Visible and near infrared spectroscopy of Hayabusa re-entry using semi-autonomous tracking

A ground-based tracking camera and co-aligned slit-less spectrograph were used to measure the spectral signature of visible radiation emitted from the Hayabusa capsule as it entered into the Earth's atmosphere in June 2010. Good quality spectra were obtained that showed the presence of radiation from the heat shield of the vehicle and the shock-heated air in front of the vehicle. An analysis of the black body nature of the radiation concluded that the peak average temperature of the surface was about (3100±100) K

Radiometric temperature analysis of the Hayabusa spacecraft re-entry

Hayabusa, an unmanned Japanese spacecraft, was launched to study and collect samples from the surface of the asteroid 25143 Itokawa. In June 2010, the Hayabusa spacecraft completed it’s seven year voyage. The spacecraft and the sample return capsule (SRC) re-entered the Earth’s atmosphere over the central Australian desert at speeds on the order of 12 km/s. This provided a rare opportunity to experimentally investigate the radiative heat transfer from the shock-compressed gases in front of the sample return capsule at true-flight conditions. This paper reports on the results of observations from a tracking camera situated on the ground about 100 km from where the capsule experienced peak heating during re-entry

Causes of death in Vanuatu

Background The population of the Pacific Melanesian country of Vanuatu was 234,000 at the 2009 census. Apart from subsistence activities, economic activity includes tourism and agriculture. Current completeness of vital registration is considered too low to be usable for national statistics; mortality and life expectancy (LE) are derived from indirect demographic estimates from censuses/surveys. Some cause of death (CoD) data are available to provide information on major causes of premature death. Methods Deaths 2001–2007 were coded for cause (ICDv10) for ages 0–59 years from: hospital separations (HS) (n = 636), hospital medical certificates (MC) of death (n = 1,169), and monthly reports from community health facilities (CHF) (n = 1,212). Ill-defined causes were 3 % for hospital deaths and 20 % from CHF. Proportional mortality was calculated by cause (excluding ill-defined) and age group (0–4, 5–14 years), and also by sex for 15–59 years. From total deaths by broad age group and sex from 1999 and 2009 census analyses, community deaths were estimated by deduction of hospital deaths MC. National proportional mortality by cause was estimated by a weighted average of MC and CHF deaths. Results National estimates indicate main causes of deaths <5 years were: perinatal disorders (45 %) and malaria, diarrhea, and pneumonia (27 %). For 15–59 years, main causes of male deaths were: circulatory disease 27 %, neoplasms 13 %, injury 13 %, liver disease 10 %, infection 10 %, diabetes 7 %, and chronic respiratory disease 7 %; and for females: neoplasms 29 %, circulatory disease 15 %, diabetes 10 %, infection 9 %, and maternal deaths 8 %. Infection included tuberculosis, malaria, and viral hepatitis. Liver disease (including hepatitis and cancer) accounted for 18 % of deaths in adult males and 9 % in females. Non-communicable disease (NCD), including circulatory disease, diabetes, neoplasm, and chronic respiratory disease, accounted for 52 % of premature deaths in adult males and 60 % in females. Injuries accounted for 13 % in adult males and 6 % in females. Maternal deaths translate into an annual maternal mortality ratio of 130/100,000 for the period. Conclusion Vanuatu manifests a double burden of disease with significant proportional mortality from perinatal disorders and infection/pneumonia <5 years and maternal mortality, coupled with significant proportional mortality in adults (15–59 years) from cardiovascular disease (CVD), neoplasms, and diabetes

Design and Characterization of a Hypervelocity Expansion Tube Facility

We report on the design and characterization of a 152 mm diameter expansion tube capable of accessing a range of high enthalpy test conditions with Mach numbers up to 7.1 for aerodynamic studies. Expansion tubes have the potential to offer a wide range of test flow conditions as gas acceleration is achieved through interaction with an unsteady expansion wave rather than expansion through a fixed area ratio nozzle. However, the range of test flow conditions is in practice limited by a number of considerations such as short test time and large amplitude flow disturbances. We present a generalized design strategy for small-scale expansion tubes. As a starting point, ideal gas dynamic calculations for optimal facility design to maximize test time at a given Mach number test condition are presented, together with a correction for the expansion head reflection through a non-simple region. A compilation of practical limitations that have been identified for expansion tube facilities such as diaphragm rupture and flow disturbance minimization is then used to map out a functional design parameter space. Experimentally, a range of test conditions have been verified through pitot pressure measurements and analysis of schlieren images of flow over simple geometries. To date there has been good agreement between theoretical and experimental results

Shock tunnel studies of scramjet phenomena, supplement 8

Reports by the staff of the University of Oueensland on various research studies related to the advancement of scramjet technology are presented. These reports document the tests conducted in the reflected shock tunnel T4 and supporting research facilities that have been used to study the injection, mixing, and combustion of hydrogen fuel in generic scramjets at flow conditions typical of hypersonic flight. In addition, topics include the development of instrumentation and measurement technology, such as combustor wall shear and stream composition in pulse facilities, and numerical studies and analyses of the scramjet combustor process and the test facility operation. This research activity is Supplement 8 under NASA Grant NAGW-674

Transient temperature probe measurements in a Mach 4 nitrogen jet

Stagnation temperature measurements have been obtained in a Mach 4 free jet of nitrogen using a technique based on transient thin film heat flux probe measurements. The uncertainty in the stagnation temperature measurements depends on the probe location within the jet but is typically around ±5 K at the centre of the jet. The thin film heat flux probe technique also provides a measurement of the heat transfer coefficient of the thin film probes with an uncertainty of around ±4% at the centre of the jet. Pitot pressure measurements were also obtained within the jet. Analysis of the heat transfer coefficient results yields the Mach number and velocity profiles which are compared with results from the pitot probe measurements. Jet velocities identified using the thin film probe and the pitot probe techniques produce results with uncertainties of less than ±2% at the centre of the jet. Measurements of RMS stagnation temperature fluctuations indicate values of around 3 K at the centre of the jet to more than 10 K in the shear layer

A review of radiation heat transfer measurement for diesel engines using the two-colour method

Understanding the heat transfer processes of compression-ignition engines requires attention to both convection and radiation components. Although a number of correlations for convective heat transfer in engine environments have been implemented in simulations with some accuracy, reliable correlations for the radiant heat transfer are yet to be developed. Most radiant heat transfer correlations are configuration-dependent and fail to accommodate important physical aspects of the radiant heat transfer process in diesel engines. The development of reliable radiation heat transfer correlations requires reliable data. The two-colour method for radiation measurement has provided valuable insight into the combustion process inside direct-injection compression ignition engine. The two-colour method is a popular approach because it is cost effective and simple approach that can provide time-resolved data. The objective of this paper is to present a review of radiation heat transfer measurement in the diesel engine environment using the principles of the two-colour method. The theory, approach, issues and complications associated with the two-colour method are discussed

Experiments on oblique shock interactions with planar mixing regions

Experimental studies using supersonic mixing configurations have revealed varying degrees of shock-induced mixing augmentation. Increases in turbulent activity through shock impingement have been observed; however, it appears that such changes in turbulent activity do not necessarily translate into sustained mixing augmentation downstream. Theoretical and experimental studies indicate that mixing augmentation can be sustained by the interaction of an oblique shock wave with a discrete fuel jet, which induces significant streamwise vorticity. However, in a numerical study of shock-induced mixing augmentation of square fuel jets, it was found that the major contribution to the mixing augmentation was actually from the vorticity amplification associated with the shock-induced convergence of the jet rather than the induced streamwise vorticity. To investigate the influence of shock compression on the development of the postshock mixing region, an inviscid analysis describing the steady interaction of an oblique shock wave and a planar mixing region was developed. This model can be used to estimate parameters such as the shock trajectory, the strength of waves reflected from the interaction process, and the postshock vorticity. The present work examines the application of the inviscid interaction model in a hypersonic configuration and focuses on the details of the shock wave–mixing region interaction process

Radial conduction effects in transient heat transfer experiments

[Introduction]: Convective heat transfer data is frequently obtained from transient surface temperature measurements. Thin film resistance gauges, thermocouples, and thermochromic liquid crystals, are used in various situations to measure the surface temperature history. By assuming that uniform semi-infinite flat plate conditions apply, it is possible to express the instantaneous surface heat flux as an analytical function of the transient surface temperature[ll. Various approaches can be used to account for the presence of multi-layered substrates and finite thickness substrate effects (Schultz and Jones; Doorly and Oldfield; Guo et al), however, the effects of surface curvature are usually, neglected. - If the heat transfer data is obtained on the premise that flat plate conditions apply. then error will be introduced if the surface is actually curved. Intuitively, the magnitude of such errors will depend on how far the heat penetrates into the substrate relative to the radius of curvature of the surface. Maulardc4) derived expressions to evaluate the accuracy of the flat plate assumption in cases where the surface under consideration is curved. However, his theoretical results do not provide a convenient means of accurately accounting for surface curvature effects in the routine analysis of experimental data. The current work presents simple analytical curvature corrections for heat transfer results inferred on the assumption that flat plate conditions prevailed during the experiment. Conditions of arbitrary surface heat flux are easily accommodated with the present analysis. The accuracy of the first-order correction analysis is demonstrated by comparing results from the approximate curvature analysis with exact results for a variety of configurations under constant convective heat transfer coefficient conditions. The practical utility of the radial heat conduction modelling is evident from a number of studies in which it has already been employed (Buttsworth and Jones); Hoffs et a1; Fletcher). Nevertheless, data from a recent heat transfer probe experiment is also considered as a further practical demonstration of the present analysis