Improving meteorological information to air transport

Meteorological information and services supporting the various operations of air transport enable a safe, efficient and cost-effective operating environment for airspace users, air navigation service providers and air traffic management. The continuing pursuit towards an improved quality of observation, forecasting and decision support services is driven by an increasingly weather-sensitive society and growing impacts of hazardous weather events. This thesis provides an overview of the field of aeronautical meteorological research by introducing the organisations involved, global and regional strategies, impacts of weather on air transport, current state of the art in meteorological research and decision support systems serving air transport needs with a view of where the field should evolve next. This thesis is an attempt to highlight key findings and point the reader towards the direction of further research on the given topics. Research supporting air transport operations with the optimal use of weather information is a specialized field where advances are led by the needs of various airspace users. Research institutions for example in the United States have contributed greatly due to the severe weather impacts experienced by the National Airspace System (NAS), the ability of the Federal Aviation Administration (FAA) and the National Oceanic and Atmospheric Administration (NOAA) to direct long-term funding to solve specific aviation-related research questions. The creation and maintenance of long-lived teams of scientists and engineers working together to produce end-to-end solutions that meet the needs of the aviation industry is the key to improving meteorological information to aviation users while university research is typically shorter duration and typical does not result in operational systems. From a global perspective, research is yet to be organised in a way that would contribute to solving aviation issues beyond single research projects and/or programmes. There is a lot more the scientific community could do to develop tailored information to decision support systems used by the aviation sector, but it would require systematic investments and the establishment of research groups focusing on the applied science questions and technology transfer. This thesis provides an overview of recommended decision support system development topics with an outline of potential milestones.Tieto ilmakehän nykyisestä ja tulevasta tilasta sekä tätä tietoa ilmailun tarpeisiin tuottavat palvelut mahdollistavat turvallisen, toimivan sekä kustannustehokkaan toimintaympäristön ilmatilan käyttäjille, ilmailun palveluiden tuottajille sekä ilmatilan hallintaa toteuttaville tahoille. Vaarallisille sääilmiöille herkemmäksi kehittyvä yhteiskunta vaatii havaintojen, ennusteiden sekä päätöksenteon tukijärjestelmien jatkuvaa kehittämistä asiakkaiden tarpeisiin. Tämä lisensiaatintutkielma tarjoaa maailmanlaajuisen yleiskatsauksen ilmailun sääpalveluiden tutkimukseen ja tuotekehitykseen pyrkimyksenään esitellä keskeiset toimijat, alueelliset ja kansalliset kehittämisohjelmat ja strategiat, sään vaikutukset ilmailulle, ilmailun sääpalveluiden nykytila sekä tulevaisuuden toimintaympäristön edellyttämät uudet lentosääpalvelut. Tavoitteena on korostaa ilmailun kannalta tärkeimpiä meteorologisia kehityskohteita ja ohjata lukija jo tehdyn tutkimuksen pariin. Ilmailun toimintoja tukevien sääpalveluiden kehittämiseen tähtäävä tutkimus on hyvin soveltava erikoisala, missä asiakkaiden tarpeet määrittävät tutkimuskohteet. Kehitys on keskittynyt voimakkaasti Yhdysvaltoihin, mihin on syynä kapasiteetin äärirajoilla toimiva ilmatila sekä kyky rahoittaa pitkäkestoisia meteorologisia tutkimushankkeita ilmailun tarpeisiin. Meteorologian tutkijoiden ja insinöörien pitkäkestoinen yhteistyö tuottaa koko arvoketjun kattavia projekteja, joiden lopputuloksena syntyy asiakkaan tarpeisiin räätälöityjä palveluita hyödyntäen yliopistoissa tehtävää tutkimusta sekä tietoteknisten ratkaisujen kehittymistä. Maailmanlaajuisesti katsottuna ilmailun sääpalveluiden tutkimusta ja tuotekehitystä ei ole toistaiseksi järjestetty yhtenäisen strategian tai tavoitteiden alle. Tieteellinen yhteisö pystyisi kasvattamaan merkittävästi panostaan ilmailun turvallisuuden kehittämiseksi, mikäli tuotekehityksen rahoitus organisoitaisiin paremmin ja osaaminen keskitettäisiin soveltavan tutkimuksen ryhmiin. Tämä tutkielma sisältää suosituksia päätöksenteon tukijärjestelmiin integroitavista sääpalveluista, joiden avulla säätilan vaikutus lentotoiminnalle voidaan viedä suoraan päätöksentekotasolle. Tutkielmassa esitettyjen projektiaihioiden tarkoituksena esittää konkreettisia toimenpiteitä, joilla varmistutaan tutkimuksen soveltuvuudesta loppukäyttäjien toimintaan

Improving meteorological information to air transport

Meteorological information and services supporting the various operations of air transport enable a safe, efficient and cost-effective operating environment for airspace users, air navigation service providers and air traffic management. The continuing pursuit towards an improved quality of observation, forecasting and decision support services is driven by an increasingly weather-sensitive society and growing impacts of hazardous weather events. This thesis provides an overview of the field of aeronautical meteorological research by introducing the organisations involved, global and regional strategies, impacts of weather on air transport, current state of the art in meteorological research and decision support systems serving air transport needs with a view of where the field should evolve next. This thesis is an attempt to highlight key findings and point the reader towards the direction of further research on the given topics. Research supporting air transport operations with the optimal use of weather information is a specialized field where advances are led by the needs of various airspace users. Research institutions for example in the United States have contributed greatly due to the severe weather impacts experienced by the National Airspace System (NAS), the ability of the Federal Aviation Administration (FAA) and the National Oceanic and Atmospheric Administration (NOAA) to direct long-term funding to solve specific aviation-related research questions. The creation and maintenance of long-lived teams of scientists and engineers working together to produce end-to-end solutions that meet the needs of the aviation industry is the key to improving meteorological information to aviation users while university research is typically shorter duration and typical does not result in operational systems. From a global perspective, research is yet to be organised in a way that would contribute to solving aviation issues beyond single research projects and/or programmes. There is a lot more the scientific community could do to develop tailored information to decision support systems used by the aviation sector, but it would require systematic investments and the establishment of research groups focusing on the applied science questions and technology transfer. This thesis provides an overview of recommended decision support system development topics with an outline of potential milestones

Car engine breather icing

Icing in an engine breather system can block the engine breather pipe, cause excessive crankcase pressure and degrade the engine performance. In this project, a numerical study, experimental tests and CFD analysis are employed in order to understand condensation and the extent of freezing inside a vertical pipe, a horizontal pipe and a T-joint pipe which are exposed to an external convective cooling. The pipe internal flow is assumed to be a vapour/air mixture. This study has led an evaluation of freezing in an engine breather pipe. The finding in this project highlighted the effects of the pipe internal flow condition (vapour mass fraction, relative humidity, mixture gas flow rate, and inlet relative humidity), the pipe external cooling condition (temperature and air velocity) and pipe thermal conductivity on condensation and extents of ice formation in the pipe. In the experimental study, a test rig has been designed and the condensation and freezing in the pipe have been tested at the Cranfield Icing Tunnel. The local pipe temperatures are measured to validate the numerical and the CFD analysis. The numerical study has led to develop a one dimensional code which used heat and mass analogy to model condensation and freezing in a vertical pipe exposed to a cold air flow (-20C). This code satisfactory predicts the trend and magnitude of the local temperatures and heat transfer coefficient along the vertical pipe at available test condition within an acceptable uncertainty of 25%. This study proposes an empirical correlation based on a degradation factor to evaluate heat transfer coefficient inside a vertical pipe. Its results fit with the experimental data within 15% uncertainty. The CFD methodology developed in this study is capable of predicting condensation rates, local temperatures, heat transfer coefficients and extent of freezing in the pipes with good agreement with the experimental results. The CFD model over predicts the breather pipe ice blockage time due to disparities between an actual engine operating condition and the CFD model. Therefore, an adjustment factor of 1.7 is proposed in this study to correlate the predicted blockage time. The results of this study can help Jaguar to establish guideline for future design of engines breather pipes

Predicción dinámica bayesiana a gran escala para series temporales de conteo

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Matemáticas, leída el 12-07-2022Dealing with uncertainty has been, and continues to be, an important problem to be taken into account in day-to-day activities of companies and governments. The uncertainty about some future values, whether it is the price of energy, the evolution of an epidemic, the intensity of rainfall, etc., poses difficulties for making adequate decisions. Therefore, the development of accurate forecasting models is of great importance. On many occasions, the uncertainty is about future observations that take non-negative integer (counts) values. For the treatment of the corresponding count time series, although the use of traditional models is possible, dedicated models that assume non-negative integer observations present numerous advantages, e.g. point forecasts that are easier to interpret and prediction intervals that will not include unfeasible values. The purpose of this industrial PhD thesis, is to contribute to the state of the art in the context of time series modeling with count data...El tratamiento de la incertidumbre ha sido, y continúa siendo, un importante problema a tener en cuenta en el día a día de empresas y gobiernos. La incertidumbre sobre ciertos valores ya sea el precio de la energía, la evolución de una epidemia, la intensidad de precipitaciones, etc., plantea dificultades para una toma de decisiones adecuada y, por lo tanto, el desarrollo de modelos de predicción precisos es de gran utilidad. En muchas ocasiones, la incertidumbre se refiere a observaciones futuras que toman valores enteros no negativos o de conteo. Para el tratamiento delas series temporales correspondientes, aunque sea posible el uso de modelos tradicionales, los modelos dedicados que consideran observaciones enteras y no negativas presentan numerosas ventajas, e.g. predicciones puntuales más fáciles de interpretar e intervalos de predicción que nunca incluyen valores no factibles. El objeto de esta tesis, resultado de la realización de un doctorado industrial, es contribuir al estado del arte en el contexto de la modelización de series temporales con datos de conteo...Fac. de Ciencias MatemáticasTRUEunpu