Large scale optimization of transonic axial compressor rotor blades

[First Paragraphs] In the present work the Multipoint Approximation Method (MAM) by Toropov et al. (1993) has been applied to the shape optimization of an existing transonic compressor rotor (NASA rotor 37) as a benchmark case. Simulations were performed using the Rolls-Royce plc. PADRAM-HYDRA system (Shahpar and Lapworth 2003, Lapworth and Shahpar 2004) that includes the parameterization of the blade shape, meshing, CFD analysis, postprocessing, and objective/constraints evaluation. The parameterization approach adopted in this system is very flexible but can result in a large scale optimization problem. For this pilot study, a relatively coarse mesh has been used including around 470,000 nodes. The parameterization was done using 5 engineering blade parameters like axial movement of sections along the engine axis in mm (XCEN), circumferential movements of sections in degrees (DELT), solid body rotation of sections in degrees (SKEW), and leading/trailing edge recambering (LEM0/TEMO) in degrees. The design variables were specified using 6 control points at 0 % (hub), 20%, 40%, 60%, 80%, and 100% (tip) along the span. Thus the total number of independent design variables N was 30. B-spline interpolation was used through the control points to generate smooth design perturbations in the radial direction

Uncertainty quantification for fat-tailed probability distributions in aircraft engine simulations

Rare event simulation is vital for industrial design because some events, so-called black swans, can have fatal consequences despite their low probability of occurrence. Finding low-probability events far off the mean design is a challenging task for realistic engineering models because they are characterized by high computational demands, many input variables, and often insufficient statistical information to build parametric probability distributions. Therefore, an adaptive and arbitrary polynomial chaos method, called sparse approximation of moment-based arbitrary polynomial chaos, is suggested in this work. Sparse approximation of moment-based arbitrary polynomial chaos creates custom polynomial basis functions and grids based on statistical moments to avoid incorrect statistical assumptions. The contribution of this work is that it is derived how rare event simulation can conveniently be integrated into adaptive sparse grid methods by calculating polynomial chaos expansions based on the statistical moments of truncated fat-tailed distributions. Moreover, the use of tempered alpha-stable distributions is suggested to avoid discontinuous tail cutoffs. Sparse approximation of moment-based arbitrary polynomial chaos is compared to other statistical methods in two industrial aircraft engine simulations: a simulation of transient cycle temperature in a turbine cavity and hot-gas ingestion in the interwheel region. In both cases, sparse approximation of moment-based arbitrary polynomial chaos agrees with previous results but obtains them with lower computational effort

Knowledge, Attitude, Lifestyle Practices, and Quality of Life in Sporadic Lymphangioleiomyomatosis Patients

Lymphangioleiomyomatosis (LAM) is a rare lung disease recognized by abnormal growth of smooth muscle cells proliferating in lungs parenchyma, developing benign tumors, migrating to the other organs, and ultimately leading to respiratory failure and death. Despite existing literature mainly on clinical aspects of LAM, there is a gap of literature in regards to the knowledge, attitude, and lifestyle practices (KAPs) of LAM patients and their effects on their quality of life. The purpose of this quantitative study was to investigate the KAPs of the sporadic LAM patients as measured by the Bristol Chronic Obstructive Pulmonary Disease Knowledge Questionnaire, Beliefs and Behavior Questionnaire, Determinants of Lifestyle Behavior Questionnaire; these KAPs were then analyzed for their relationship to quality of life reports as measured by the St George’s Quality of Life Questionnaire. Transtheoretical model (TTM) was used to describe the relationship among the variables. The data were collected through online survey questionnaires from 143 sporadic LAM patients registered at the LAM Foundation. Pearson’s correlations and linear regression were used to analyze the data. The results of the analysis showed that there was a significant positive relationship between attitude, lifestyle practices, and quality of life and a negative relationship between knowledge and quality of life. The outcome achieved by this study and its implication on social change identifies the need to initiate more study-specific KAPs within LAM populations, including individuals with tuberous sclerosis complex LAM. The results could also encourage the LAM community as well as other stakeholders to implement programs, workshops, and interventions that could promote and enhance quality of life

Treatment of a mixed industrial-domestic wastewater with biological nitrogen removal

LAUREA SPECIALISTICAL'applicazione di modelli matematici nella progettazione e il funzionamento dei sistemi biologici di rimozione dei nutrienti sta diventando sempre più importante con le legislazioni sempre più severe. I recenti sviluppi nella tecnologia informatica permesso lo sviluppo di programmi per computer che sono in grado di risolvere modelli complessi necessari per descrivere i processi che avvengono in impianti a fanghi attivi. In questo studio, i metodi per la determinazione frazioni di COD e di azoto e parametri cinetici e stechiometrici per acque reflue domestiche e industriali vengono valutati, e delle acque reflue è frazionato sulla base delle misure di piante reali e risultati di studi precedenti in letteratura. Inoltre, IWAQ Activated Sludge Model Number 1 (ASM1) viene applicata al trattamento delle acque reflue Impianto Comodepur Italia con ASM 1 run-time ambiente di simulazione. A causa delle limitazioni del software per la simulazione del comportamento di Comodepur trattamento delle acque reflue, la configurazione di riferimento del modello è stata utilizzata e denitrificazione Post non è stato incluso nello studio. Per lo più i parametri di default cinetici e stechiometrici offerti dal Gruppo IWAQ Task vengono utilizzati nelle simulazioni alcuni di loro erano stati calibrati per ottenere valori più uniformi a quelli misurati. Poiché lo studio di simulazione mancava lo studio della denitrificazione Messaggio della pianta a causa dell'incompatibilità del software, la capacità vera e carenze di impianti di trattamento delle acque reflue Comodepur non può essere determinato. Pertanto ulteriori studi proposto per la determinazione della capacità organica ed efficienza di rimozione di azoto. Quindi è dimostrato che il destino dei componenti carboniosi e azotati di acque reflue e di concentrazione MLSS in vasche di aerazione richiede analisi di sensibilità per la calibrazione del modello in modo che la risposta della pianta a varie condizioni può essere stimato utilizzando ASM1. Per WWTPs con disegno complesso lay out e alti volumi di influenti uso di ASM 1 non è raccomandato e invece più recenti e le più recenti versioni di JASS modelli di fango attivo sono raccomandati per studi futuri. Parole chiave: modellazione, ASM1, processo a fanghi attivi, rimozione dell'azoto, trattamento delle acque reflue, la rimozione COD.Application of mathematical models in design and operation of biological nutrient removal systems is becoming more important with the legislations getting stricter. Recent developments in computer technology enabled development of computer programs that are able to solve complex models required to describe the processes taking place in activated sludge plants. In this study, methods for determining COD and nitrogen fractions and kinetic and stoichiometric parameters for domestic and industrial wastewaters are evaluated, and wastewater is fractionated using actual plant measurements and results of previous studies in literature. In addition, IWAQ Activated Sludge Model Number 1 (ASM1) is applied to Comodepur Wastewater Treatment Plant Italy using ASM 1 run-time simulation environment. Due to limitations of the software for simulating the behavior of Comodepur WWTP, benchmark configuration of the model had been used and Post Denitrification has not been included in the study. Mostly default kinetic and stoichiometric parameters offered by IWAQ Task Group are used in simulations some of them had been calibrated to get closer values to the measured ones. Since the simulation study lacked the study of Post Denitrification of the plant because of the incompatibility of the software, true capacity and shortcomings of Comodepur Waste water treatment plant cannot be determined. Therefore further study is proposed for determination of the Organic capacity and Nitrogen Removal efficiency. Therefore it is shown that the fate of carbonaceous and nitrogenous components of wastewater and MLSS concentration in aeration tanks requires sensitivity analysis for model calibration so that plant’s response to various conditions can be estimated using ASM1. For WWTPs with complex design lay out and high influent volumes use of ASM 1 is not recommended and instead newer and latest versions of JASS Activated Sludge Models are recommended for future studies. Keywords: Modeling, ASM1, Activated Sludge Process, Nitrogen Removal, Waste water treatment plant, COD Removal