Autor: Jordan, O. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Computational modelling of the fuel injection and combustion in a Diesel K6 rotary engine
Autorzy:: Mason, M.
Wyszyński, M. L.
Jordan, O.
Gibson, D.
Tematy:: combustion engine
combustion process
combustion factors
fuel injection
ANSYS Fluent code; Pokaż więcej
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Powiązania:: https://bibliotekanauki.pl/articles/243793.pdf Link otwiera się w nowym oknie
Opis:: This paper outlines the methods and results of computations completed using the ANSYS Fluent code modelling the fuel injection and combustion within the K6 engine, a new form of rotary engine in which the fuel is injected in an arc across the top of the cylinder. The model uses the DPM Model in conjunction with a dynamic mesh and non-premixed combustion models to treat the injection as liquid diesel evaporating to C12H23. The outcomes of this model are presented in images displaying the distribution of temperature, and fuel and CO2 concentrations. The limitations pertaining to the maximum injection angles are also studied. The simulation is found to be effective and the results suggestive of successful, clean and complete combustion while presenting some matters, which require further investigation. The article presents temperature within the combustion chamber at various crank angle degrees, ) velocity of fluid within the combustion chamber, effects of impingement with injector offset on temperature and fuel concentration, fuel concentration demonstrating impingement, in cylinder temperature curve.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Optimisation of virtual monoenergetic reconstructions for the diagnosis of pulmonary embolism using photon-counting detector computed tomography angiography
Autorzy:: Kabakus, Ismail M.
Knight, Heather
Maisuria, Dhruw
Schoepf, U. Joseph
Hinen, Shaun
Baruah, Dhiraj
Toth, Adrienn
McGuire, Aaron
Munden, Reginald F.
Chamberlin, Jordan H.
O’Doherty, Jim
Opis:: Purpose: Computed tomography (CT) pulmonary angiography is considered the gold standard for pulmonary embolism (PE) diagnosis, relying on the discrimination between contrast and embolus. Photon-counting detector CT (PCD-CT) generates monoenergetic reconstructions through energy-resolved detection. Virtual monoenergetic images (VMI) at low keV can be used to improve pulmonary artery opacification. While studies have assessed VMI for PE diagnosis on dual-energy CT (DECT), there is a lack of literature on optimal settings for PCD-CT-PE reconstructions, warranting further investigation. Material and methods: Twenty-five sequential patients who underwent PCD-CT pulmonary angiography for suspicion of acute PE were retrospectively included in this study. Quantitative metrics including signal-to-noise ratio (SNR) and contrast-to-noise (CNR) ratio were calculated for 4 VMI values (40, 60, 80, and 100 keV). Qualitative measures of diagnostic quality were obtained for proximal to distal pulmonary artery branches by 2 cardiothoracic radiologists using a 5-point modified Likert scale. Results: SNR and CNR were highest for the 40 keV VMI (49.3 ± 22.2 and 48.2 ± 22.1, respectively) and were inversely related to monoenergetic keV. Qualitatively, 40 and 60 keV both exhibited excellent diagnostic quality (mean main pulmonary artery: 5.0 ± 0 and 5.0 ± 0; subsegmental pulmonary arteries 4.9 ± 0.1 and 4.9 ± 0.1, respectively) while distal segments at high (80-100) keVs had worse quality. Conclusions: 40 keV was the best individual VMI for the detection of pulmonary embolism by quantitative metrics. Qualitatively, 40-60 keV reconstructions may be used without a significant decrease in subjective quality. VMIs at higher keV lead to reduced opacification of the distal pulmonary arteries, resulting in decreased image quality.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego