A Comparison Study of EDR Estimates from the NLR and NCAR Algorithms

A comparison was made of two eddy dissipation rate (EDR) estimates based on flight data recorded by commercial flights. The EDR estimates from real-time data using the National Center for Atmospheric Research (NCAR) Algorithm were compared with the EDR estimates derived using the Netherlands Aerospace Centre (NLR) Algorithm using quick assess recorder (QAR) data. The estimates were found to be in good agreement in general, although subtle differences were found. The agreement between the two algorithms was better when the flight was above 10,000 ft. The EDR estimates from the two algorithms were also compared with the vertical acceleration experienced by the aircraft. Both EDR estimates showed good correlation with the vertical acceleration and would effectively capture the turbulence subjectively experienced by pilots.

Travel Bubbles in Air Transportation: Myth or Reality?

Aviation has been hit hard by COVID-19, with passengers stranded in remote destinations, airlines filing for bankruptcy, and uncertain demand scenarios for the future. Travel bubbles are discussed as one possible solution, meaning countries which have successfully constrained the spread of COVID-19 gradually increase their mutual international flights, returning to a degree of normality. This study aims to answer the question of whether travel bubbles are indeed observable in flight data for the year 2020. We take the year 2019 as reference and then search for anomalies in countries’ flight bans and recoveries, which could possibly be explained by having successfully implemented a travel bubble. To the best of our knowledge, this study is the first to try to address the identification of COVID-19 travel bubbles in real data. Our methodology and findings lead to several important insights regarding policy making, problems associated with the concept of travel bubbles, and raise interesting avenues for future research.

The Applicability of eVTOLs in Emergency Medical Care in Japan

Background: The present study aims to elucidate the applicability of electric vertical takeoff and landing (eVTOL) aircraft that dispatch only a doctor to provide a solution to the operational challenges of utilizing a helicopter to transport a doctor to the patient/s, with such physician-staffed emergency medical helicopters being known as doctor heli (DH), in Japan.Methods: This study conducted interviews with 17 parties related to DHs in five prefectures in Japan to depict challenges of DHs and eVTOL requirements. Subsequently, this study analyzed the Hokusoh DH flight data, as an example, in terms of cases for which flight doctors consider condition assessment and initial treatment provision by a doctor would be particularly effective, to assess the hypothesis that a two-seater is applicable for emergency medical care (EMS) and that eVTOLs help reduce duplicate dispatch requests for DHs as well as the percentage and delayed dispatch time of duplicate requests.Results: Challenges of DHs and eVTOL requirements were identified and classified into six major categories. Data analysis results indicated that two-seater eVTOLs would be particularly effective for trauma, cardiac disease, brain disease cases, and pediatric patient cases and help solve duplicate requests.Conclusions: Two-seater eVTOLs are likely applicable in EMS in Japan.

Aerodynamic design, analysis, and validation techniques for the Tianwen-1 entry module

The clear differences between the atmosphere of Mars and the Earth coupled with the lack of a domestic research basis were significant challenges for the aerodynamic prediction and verification of Tianwen-1. In addition, the Mars entry, descent, and landing (EDL) mission led to specific requirements for the accuracy of the aerodynamic deceleration performance, stability, aerothermal heating, and various complex aerodynamic coupling problems of the entry module. This study analyzes the key and difficult aerodynamic and aerothermodynamic problems related to the Mars EDL process. Then, the study process and results of the design and optimization of the entry module configuration are presented along with the calculations and experiments used to obtain the aerodynamic and aerothermodynamic characteristics in the Martian atmosphere. In addition, the simulation and verification of the low-frequency free oscillation characteristics under a large separation flow are described, and some special aerodynamic coupling problems such as the aeroelastic buffeting response of the trim tab are discussed. Finally, the atmospheric parameters and aerodynamic characteristics obtained from the flight data of the Tianwen-1 entry module are compared with the design data. The data obtained from the aerodynamic design, analysis, and verification of the Tianwen-1 entry module all meet the engineering requirements. In particular, the flight data results for the atmospheric parameters, trim angles of attack, and trim axial forces are within the envelopes of the prediction deviation zones.

Method of Separating Cosmic-Ray Positrons from Electrons in the DAMPE Experiment

A method of identifying positron/electron species from the cosmic rays was studied in the DAMPE experiment. As there is no onboard magnet on the satellite, the different features imposed by the geomagnetic field on these two species were exploited for the particle identification. Application of this method to the simulation of on-orbit electrons/positrons/protons and the real flight data proves that separately measuring the CR positrons/electrons with DAMPE is feasible, though limited by the field of view for the present observation data. Further analysis on the positron flux with this method can be expected in the future.