Xavier Llamas
A5009488435- Advanced Combustion Engine Technologies
- Real-time simulation and control systems
- Pulsars and Gravitational Waves Research
- Hydraulic and Pneumatic Systems
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Turbomachinery Performance and Optimization
- Computational Physics and Python Applications
- Catalytic Processes in Materials Science
- Maritime Transport Emissions and Efficiency
- Refrigeration and Air Conditioning Technologies
- Electric and Hybrid Vehicle Technologies
- Advanced Measurement and Metrology Techniques
- Industrial Technology and Control Systems
- Scientific Measurement and Uncertainty Evaluation
- Modeling, Simulation, and Optimization
- Vehicle emissions and performance
- Particle Accelerators and Free-Electron Lasers
- Advanced Electrical Measurement Techniques
- Atmospheric Ozone and Climate
- Soil Moisture and Remote Sensing
- Advanced Frequency and Time Standards
- Scientific Research and Discoveries
- Industrial Gas Emission Control
- Gear and Bearing Dynamics Analysis
Applus+ IDIADA (Spain)
2021
Sener (Spain)
2020
VSL Systems (Sweden)
2020
Linköping University
2014-2018
In this paper, we describe the current status of LISA Pathfinder mission, a precursor mission aimed at demonstrating key technologies for future spacebased gravitational wave detectors, like LISA.Since much flight hardware has already been constructed and tested, will show that performance measurements analysis these components lead to an expected which is significant improvement over requirements, actually reaches requirements entire measurement band.
This paper presents a quantitative assessment of the performance upcoming LISA Pathfinder geodesic explorer mission. The findings are based on results extensive ground testing and simulation campaigns using flight hardware, control operations algorithms. show that, for central experiment measuring stray differential acceleration between test masses, will be able to verify overall noise within factor 2 requirement at 1 mHz 6 0.1 mHz. We also discuss key elements physical model disturbances,...
LISA Pathfinder, the second of European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology demonstrator joint ESA/NASA Laser Interferometer Antenna (LISA) mission. The technologies required are many and extremely challenging. This coupled with fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise led implementation Pathfinder mission test critical environment. essentially mimics one arm constellation by...
Preparations for the LISA Pathfinder mission have reached an exciting stage.Tests of engineering model (EM) optical metrology system recently been completed at Albert Einstein Institute, Hannover, and flight tests are now underway.Significantly, they represent first complete integration testing space-qualified hardware on level.The results test procedures these campaigns will be utilized directly in ground-based tests, subsequently during in-flight operations.In addition, allow valuable data...
A nonlinear mean value engine model (MVEM) of a two-stroke turbocharged marine diesel is developed, parameterized and validated against measurement data. The goal to have computationally fast accurate that captures the main dynamics can be used in development control systems for newly introduced EGR system. tuning procedure explained, result six-state MVEM with seven inputs capture system dynamics.
As the launch of LISA Pathfinder (LPF) draws near, more and effort is being put in to preparation data analysis activities that will be carried out during mission operations.The operations phase composed a series experiments on satellite.These directed analysed by team, which part team.The last about 90 days, time team aims fully characterize LPF, particular, its core instrument Technology Package.By analysing various couplings present system, different noise sources disturb through...
A complete and compact control-oriented compressor model consisting of a mass flow submodel an efficiency is described. The final application the two-stroke mean value engine (MVEM) which requires simulating operating at low-flow low-pressure ratio area. based on previous research done for automotive-size compressors, it shown to be general enough adapt well characteristics marine-size compressors. physics-based allows, together with model, extrapolating ratios. complexity makes its...
Utilization of natural gas fuels in heavy duty vehicles offers an effective solution to reduce global warming and improve urban air quality. However, there are problems related catalyst durability release unburned methane (methane slip). Catalyst can be achieved through clever designs both material its regeneration process. In this paper, we studied extensively low temperature strategies a commercial oxidation (MOC), three-way (TWC) diesel (DOC) as well two coupled catalysts; TWC-MOC...
Large marine two-stroke diesel engines are widely used as propulsion systems for shipping worldwide and facing stricter NO x emission limits. Exhaust gas recirculation is introduced to these reduce the produced combustion allowed levels. Since current number of built with exhaust low engine testing very expensive, a powerful alternative developing controllers such use control-oriented simulation models. Unfortunately, same reasons that motivate models also hinder capacity obtain sufficient...
Downsizing and turbocharging with single or multiple stages has been one of the main solutions to decrease fuel consumption harmful exhaust emissions, while keeping a sufficient power output. A ...
In modern turbocharged engines the power output is strongly connected to turbocharger speed, through flow characteristics of turbocharger. Turbo speed therefore an important state fo ...
Exhaust Gas Recirculation (EGR) was recently introduced in large marine two-stroke diesel engines to reduce NOx-emissions. Controlling EGR flow during accelerations, while keeping good acceleration performance is challenging, due delays the scavenge receiver oxygen measurement and upper limits on fuel for avoiding black smoke. Previous feedback controllers struggled but a new EGR-controller based adaptive feedforward (AFF) has been successful. Nevertheless, further analysis tests are...
Spectr-UV/WSO-UV is the third and last of Spektr missions (Spektr-Radio, Spektr-RG, Spektr-UF), space-based observatories, Russian Scientific Space Program. Spektr-UF/WSO-UV a 2-m class ultraviolet (UV) observatory to be set in geosynchronous orbit 2025 from Vostochny launching pad. The equipped with instrumentation for UV spectroscopy imaging. Universidad Complutense de Madrid together Institute Astronomy Academy Sciences are developing jointly imaging instrument mission. has UV-optical...
LISA Pathfinder is a mission planned by the European Space Agency to test key technologies that will allow detection of gravitational waves in space. The instrument on-board, Technology package, undergo an exhaustive campaign calibrations and noise characterisation campaigns order fully describe model. Data analysis plays important role for reason data team has been developing toolbox which contains all functionalities required during operations. In this contribution we give overview recent...
A mean value engine model of a two-stroke ma-rine diesel with EGR that is capable simulatingduring low load operation developed. In order to beable perform simulations, c ...
Exhaust Gas Recirculation (EGR) has recently been introduced in large marine two-stroke diesel engines to reduce NOx emissions. During accelerations, controlling the amount of EGR flow while still keeping good acceleration performance can be quite challenging. The main difficulties overcome are delay scavenge receiver oxygen measurement and upper limit fuel that burned with diluted air without producing black smoke. Previous feedback controllers struggled during but a new approach control...
A mean value engine model of a two-stroke marine diesel with EGR that is capable simulating during low load operation developed.In order to be able perform simulations, compressor speed extrapolation also investigated and parameterized for two different compressors.Moreover, parameterization procedure get good parameters both stationary dynamic simulations described applied.The validated layouts the same test but turbocharger units.The simulation results show agreement measured signals,...