Theory of aerodynamic heating from molecular collision analysis

Publication date: Available online 30 October 2019Source: Physics Letters AAuthor(s): Yi Tao, Zhongwu Li, Quan Han, Chengdong Sun, Yan Zhang, Yunfei ChenAbstractAn aerodynamic heating model is derived from molecular collision analysis, in which the rising temperature of a hypersonic flying object as a function of the flying speed in a classical dense monoatomic gas environment is set up. The model predicts that the rising temperature of the hypersonic flying object is independent of the gas density but depends linearly on the gas atomic mass. A nonequilibrium molecular dynamics simulation is carried out to verify the theoretical model. Also, through analyzing the vibrational density of states in the flying objects, it is found that the excited phonon frequency is near the collision frequency, uncovering that the phonons are mainly excited by the face colliding gas atoms. Our study provides a new insight into understanding the intrinsic mechanism of aerodynamic heating and helps to develop the temperature-controllable hypersonic flying vehicle.
Source: Physics Letters A - Category: Physics Source Type: research

Related Links:

Publication date: Available online 9 December 2019Source: Journal of Physics and Chemistry of SolidsAuthor(s): Cristina Crupi, Giovanni Carini, Giuseppe Carini, Mauro Federico, Andrea Mandanici, Valentino Romano, Giovanna D'AngeloAbstractStructural changes of (Ag2O)x(B2O3)1-x glasses, over the range between X = 0.0 and X = 0.14, have been monitored by Raman spectroscopy. Low temperature heat capacity measurements have been also performed between 0.4 K and 25 K to investigate along with low frequency Raman scattering the behavior of the low-energy vibrational dynamics. A progressively decreasing intensity of the...
Source: Journal of Physics and Chemistry of Solids - Category: Physics Source Type: research
Authors: Ring B, Burbank AJ, Mills K, Ivins S, Dieffenderfer J, Hernandez ML Abstract Objectives: Objective measurements of asthma impairment could aid teens in recognition of changes in asthma status over time. Ready access to a conventional spirometer is not realistic outside of the clinical setting. In this proof-of-concept study, we compared the performance of the VitalFlo mobile spirometer to the nSpire KoKo® sx1000 spirometer for accuracy in measuring Forced Expiratory Volume in one second (FEV1) and Forced Vital Capacity (FVC) in adolescents with asthma.Methods: Two hundred forty pulmonary function measu...
Source: Journal of Asthma - Category: Respiratory Medicine Tags: J Asthma Source Type: research
Authors: Brignardello-Petersen R PMID: 31810520 [PubMed - as supplied by publisher]
Source: Journal of the American Dental Association - Category: Dentistry Tags: J Am Dent Assoc Source Type: research
Authors: Brignardello-Petersen R PMID: 31810519 [PubMed - as supplied by publisher]
Source: Journal of the American Dental Association - Category: Dentistry Tags: J Am Dent Assoc Source Type: research
Lawrence Mehren intends to retire as president and CEO of Tucson-based Accelerate Diagnostics Inc., effective Jan. 31, 2020. According to a U.S. Securities and Exchange Commission filing, Mehren will also give up his seat as a director of the publicly traded company, but will take on a part-time role with the medical diagnostics company immediately after his retirement. Mehren will be replaced as CEO by Jack Phillips, currently the company's chief operating officer, effective Feb. 1. Phillips,…
Source: bizjournals.com Health Care:Biotechnology headlines - Category: Biotechnology Authors: Source Type: news
Org. Biomol. Chem., 2019, Accepted Manuscript DOI: 10.1039/C9OB02467K, PaperLuis R. Domingo, Mar Rios-Gutierrez, Patricia Perez The enhanced reactivity of a series of four aza aromatic compounds (AACs) participating in the Diels-Alder (DA) reactions with ethylene has been studied within the Molecular Electron Density Theory (MEDT).... The content of this RSS Feed (c) The Royal Society of Chemistry
Source: RSC - Organic and Biomolecular Chemistry - Category: Molecular Biology Authors: Source Type: research
Org. Biomol. Chem., 2019, Accepted Manuscript DOI: 10.1039/C9OB02415H, PaperXiahe Chen, Qunmin Wang, Hai-Min Shen, Guijie Li, Yun-Fang Yang, Yuan-Bin She The mechanism and origins of stereoselectivity of asymmetric benzylic C –H hydroxylation by Ru-porphyrin were elucidated with density functional theory calculations. The reaction proceeds via a hydrogen-atom abstraction/oxygen-rebound pathway, wherein a... The content of this RSS Feed (c) The Royal Society of Chemistry
Source: RSC - Organic and Biomolecular Chemistry - Category: Molecular Biology Authors: Source Type: research
[Radio Dabanga] Kassala -Dengue fever rates in Kassala last week recorded a marked decline, ranging from 36 to 90 cases per day.
Source: AllAfrica News: Health and Medicine - Category: African Health Source Type: news
[Radio Dabanga] Khartoum -On Thursday, a large medical convoy left the Sudanese capital, heading to the Nuba Mountains in South Kordofan where it will offer free treatment to the victims of war in the region.
Source: AllAfrica News: Health and Medicine - Category: African Health Source Type: news
[Daily Maverick] The Helen Suzman Foundation makes a case for the National Health Insurance Bill to be withdrawn.
Source: AllAfrica News: Health and Medicine - Category: African Health Source Type: news
More News: Environmental Health | Physics | Study