Gas turbine engine emission reduction technology program

Progress in the development of combustor technology to meet the standards for the allowable pollutant emission levels of aircraft gas turbine engines is reported. The high-bypass-ratio turbofan engines which power the large commercial aircraft were emphasized along with efforts to reduce emission for near term applications. Recommendations for continuing research to reduce emissions to meet far term needs are given

Photographic study of propellant outflow from a cylindrical tank during weightlessness

Photographic study of liquid propellant behavior in pumping from cylindrical tank during weightlessnes

EFFECT OF CONTACT ANGLE AND TANK GEOMETRY ON THE CONFIGURATION OF THE LIQUID-VAPOR INTERFACE DURING WEIGHTLESSNESS

Effect of contact angle and space vehicle tank geometry on configuration of rocket propellant liquid-vapor interface during weightlessnes

Results and status of the NASA aircraft engine emission reduction technology programs

The results of an aircraft engine emission reduction study are reviewed in detail. The capability of combustor concepts to produce significantly lower levels of exhaust emissions than present production combustors was evaluated. The development status of each combustor concept is discussed relative to its potential for implementation in aircraft engines. Also, the ability of these combustor concepts to achieve proposed NME and NCE EPA standards is discussed

Systematic review with radiomics quality score of cholangiocarcinoma: an EuSoMII Radiomics Auditing Group Initiative

Objectives To systematically review current research applications of radiomics in patients with cholangiocarcinoma and to assess the quality of CT and MRI radiomics studies. Methods A systematic search was conducted on PubMed/Medline, Web of Science, and Scopus databases to identify original studies assessing radiomics of cholangiocarcinoma on CT and/or MRI. Three readers with different experience levels independently assessed quality of the studies using the radiomics quality score (RQS). Subgroup analyses were performed according to journal type, year of publication, quartile and impact factor (from the Journal Citation Report database), type of cholangiocarcinoma, imaging modality, and number of patients. Results A total of 38 original studies including 6242 patients (median 134 patients) were selected. The median RQS was 9 (corresponding to 25.0% of the total RQS; IQR 1-13) for reader 1, 8 (22.2%, IQR 3-12) for reader 2, and 10 (27.8%; IQR 5-14) for reader 3. The inter-reader agreement was good with an ICC of 0.75 (95% CI 0.62-0.85) for the total RQS. All studies were retrospective and none of them had phantom assessment, imaging at multiple time points, nor performed cost-effectiveness analysis. The RQS was significantly higher in studies published in journals with impact factor > 4 (median 11 vs. 4, p = 0.048 for reader 1) and including more than 100 patients (median 11.5 vs. 0.5, p < 0.001 for reader 1). Conclusions Quality of radiomics studies on cholangiocarcinoma is insufficient based on the radiomics quality score. Future research should consider prospective studies with a standardized methodology, validation in multi-institutional external cohorts, and open science data

Low Gravity Issues of Deep Space Refueling

This paper discusses the technologies required to develop deep space refueling of cryogenic propellants and low cost flight experiments to develop them. Key technologies include long term storage, pressure control, mass gauging, liquid acquisition, and fluid transfer. Prior flight experiments used to mature technologies are discussed. A plan is presented to systematically study the deep space refueling problem and devise low-cost experiments to further mature technologies and prepare for full scale flight demonstrations

Эффективность парокомпрессионной трансформации энергетических потоков для теплоснабжения на основе морской воды

The results of the analytical study substantiated the operating conditions for the highly efficient use of the temperature potential of seawater in heat pump heating systems (HPHS) for buildings a building with correspondingly improved environmental indicators. Based on the analysis of the regional conditions of the Odessa water area of the Black Sea, the initial parameters have been substantiated and rational modes of operation of an improved HPHS with central, decentralized or local heating of the subscriber energy carrier have been determined. As indicators for evaluating the efficiency of the HPHS operation, the conversion factor of energy flows and the specific consumption of external energy for the drive of the compressor and the circulating pump of cooled water in the operation of heat pump units were considered. For seawater in the Odessa water area of the Black Sea during the entire heating period, the following temperatures were considered as initial data for analysis: water at the inlet to the evaporator (5–10) ° C, at the outlet (1 °C); calculated temperature difference of the coolant in the heating system (50–40) °C, indoor air (20 °C); estimated outdoor temperature (–18 °C). The characteristic correspondence between the flow rates of the cooled sea water and the heated energy carrier of the heat supply system was taken into account. The prerequisites of high efficiency of the heat pump heat supply system in which the actual conversion coefficient exceeds the seasonal normalized calculated and minimum value at an outdoor temperature of (–10) °C under the limiting conditions of the monoenergy regime for both new and reconstructed buildings were substantiated. In the course of the study, it has been determined that the total specific consumption of external energy for the compressor drive and the circulation of cooled water in the operation of a heat pump unit with a characteristic ratio of water equivalents, even under the limiting conditions of the monoenergetic mode of operation of the heat supply system at an outdoor temperature of (–10) °C, are within the range of generally accepted values (w = 0.28–0.34).В статье результатами аналитического исследования обоснованы режимные условия высокоэффективного использования температурного потенциала морской воды в теплонасосных системах теплоснабжения зданий с соответствующим улучшением экологических показателей окружающей среды. На основе анализа региональных условий Одесской акватории Черного моря определены исходные параметры и рациональные режимы работы усовершенствованной теплонасосной системы с центральным, децентрализованным либо локальным догревом абонентского энергоносителя. Показателями оценки эффективности теплонасосных систем в исследовании приняты коэффициент преобразования энергетических потоков, удельные затраты внешней энергии на привод компрессора и циркуляционного насоса охлаждаемой воды в работе теплонасосной установки. На протяжении всего отопительного периода в качестве исходных рассматривались следующие данные: температура воды на входе в испаритель (5–10) °С, на выходе 1 °С; расчетный перепад температур теплоносителя в системе отопления (50–40) °С, воздуха внутри помещения 20 °С; расчетная температура наружного воздуха (–18) °С. Учитывалось характерное соотношение расходов охлаждаемой морской воды и нагреваемого энергоносителя системы теплоснабжения. Обоснованы условия высокой эффективности работы теплонасосной системы теплоснабжения, при которых действительный коэффициент преобразования превышает сезонное нормированное расчетное и минимальное значения при температуре наружного воздуха (–10) °С в предельных условиях моноэнергетического режима как для новых, так и для реконструируемых зданий. В ходе исследования установлено, что общие удельные затраты внешней энергии на привод компрессора и циркуляцию охлаждаемой воды в работе теплонасосной установки с характерным соотношением водяных эквивалентов даже в предельных условиях моноэнергетического режима эксплуатации системы теплоснабжения при температуре наружного воздуха (–10) °С находятся в диапазоне общепринятых значений (w = 0,28–0,34)

Концепция устройства и энергетический потенциал парокомпрессионного теплохладоснабжения на основе бинарного низкотемпературного источника

The combined use of low-potential soil heat and air flows in heat pump heat supply systems allows for its regulated redistribution in the processes of customers’ consumption. Herewith, the intensity of energy extraction by the soil heat exchanger decreases, excess heat is accumulated with a decrease in the depth of wells, and the costs of installing and operating probe heat exchangers are also reduced. An improved version of the conceptual arrangement of a vapor compression system for heat and cool supply of buildings based on the integrated heat of soil and ventilation air has been developed. Its distinguished features are the possibility of automatic redistribution of generated heat flows in the subsystems of customers’ heat consumption and accumulation of excess part in the soil mass. When the system is operating in the warm season with the extraction of heat only for hot water supply, there is a more intensive accumulation of excess heat of the ventilation air in the soil mass, which restores its temperature in the accumulation mode for further use with the coming of the heating period. Multifactor analytical dependences of the heat flows of the main equipment have been established, taking into account the initial parameters and operating conditions of the structural subsystems for the extraction, transformation and consumption of heat, which are the basis for determining the energy potential of vapor compression heat and cold supply using a binary low-temperature source.Совместное использование низкопотенциальной теплоты грунта и воздушных потоков в теплонасосных системах теплоснабжения позволяет осуществлять ее регулируемое перераспределение в процессах абонентского потребления. При этом снижается интенсивность отбора энергии грунтовым теплообменником, избыточная теплота аккумулируется с уменьшением глубины скважин, а также сокращаются затраты на устройство и эксплуатацию зондовых теплообменников. Разработан усовершенствованный вариант концептуального устройства парокомпрессионной системы теплохладоснабжения зданий на основе интегрированной теплоты грунта и вентиляционного воздуха, отличающийся возможностью автоматического перераспределения генерируемых тепловых потоков в подсистемах абонентского теплопотребления и аккумулирования избыточной части в грунтовом массиве. При работе системы в теплый период года с отбором теплоты только на горячее водоснабжение происходит более интенсивное аккумулирование избыточной теплоты вентиляционного воздуха в грунтовом массиве, который восстанавливает свою температуру в режиме аккумулирования для дальнейшего использования с наступлением отопительного периода. Установлены многофакторные аналитические зависимости тепловых потоков основного оборудования, учитывающие исходные параметры и режимные условия работы структурных подсистем отбора, трансформации и потребления теплоты, которые являются основой для определения энергетического потенциала парокомпрессионного теплохладоснабжения с использованием бинарного низкотемпературного источника.

Radial distribution of a single-pass amplified radiation in the active elements of CuBr lasers

The paper presents the results of study of single-pass amplified radiation distribution of copper bromide vapor laser active elements used in high-speed laser monitors. The possibility of modifying the profile of a single-pass amplified light beam by changing the copper bromide vapor concentration is demonstrated. This means of influence on the radiation profile seems to be easiest due to implementation by varying only one parameter of operation. Gaussian, ring-shaped or flat profiles can be achieved depending on the temperature of the containers with copper bromide. The diameter of the beam becomes narrower when increasing the concentration of copper bromide vapor. This feature is characteristic of the discharge tubes as small (diameter 2.5, length 5 cm) and large (diameter 5 cm, length 90 cm) active volume