Climate Assessment of Hydrogen Combustion Aircraft: Towards a Green Aviation Sector

As climate change aggravates, the aviation sector strives to minimize its climate footprint. To this end, international organizations, such as ICAO and ACARE, are promoting mitigation measures including novel technologies, operations, and energy carriers to reduce aircraft emissions significantly. Hydrogen (H2) as an alternative fuel has the...

Minimizing the climate impact of the next generation aircraft using novel climate functions for aircraft design

The aircraft’s environmental performance on fleet level is so far completely decoupled from the design process. The climate impact from aviation arising from non-CO2 effects are largely independent from CO2 emissions, but rather depend on the atmospheric state. Previously complex climate-chemistry models were used to evaluate the non-CO2...

A Novel Engine Architecture for Low NOx Emissions

The fuel efficiency of turbofan engines has improved significantly, hence reducing aviation's CO2 emissions. However, the increased operating pressure and temperature for fuel efficiency cause adverse effects on NOx emissions. Therefore, a novel engine concept, which can reduce NOx emissions without affecting the cycle efficiency, is of high...

A Ring-Oscillator Sub-Sampling PLL With Hybrid Loop Using Generator-Based Design Flow

We present a ring-oscillator-based sub-sampling phase-locked loop (PLL) using a generator-based design flow. A hybrid loop with a delta-sigma ($\Delta \Sigma$) modulator is applied to reduce the loop filter (LF) area and the control ripple. The generator automatically produces the ring oscillator and PLL to meet the provided specifications. The...

A 200Gb/s PAM-4 Transmitter with Hybrid Sub-Sampling PLL in 28nm CMOS Technology

This paper presents a complete 200Gb/s PAM-4 transmitter (TX) in 28nm CMOS technology. The transmitter features a hybrid sub-sampling PLL (SSPLL) with a delta-sigma (?S) modulator, clock distribution network with flexible timing control, and data path with a hybrid 5-tap Feed-Forward Equalizer (FFE) and T-coil for bandwidth extension. The...

Seasonal Variability of Aircraft Trajectories reducing NOx-climate Impacts under a Multitude of Weather Patterns

Air traffic contributes to global warming through CO2 and non-CO2 effects, including the impact of NOx emissions on atmospheric ozone and methane, formation of contrails, and changes in the amount of stratospheric water vapour. The climate impact of non-CO2 effects is highly dependent on the background atmospheric conditions at the time and...

A molecular dynamics study of N-A-S-H gel with various Si/Al ratios

The understanding of sodium aluminosilicate hydrate (N-A-S-H) gel is still limited due to its complex and amorphous structure. Recently, molecular dynamics simulation has provided a unique opportunity to better understand the structure of N-A-S-H gel from nanoscale. In this work, the N-A-S-H gel structure was obtained by simulating the...

Operating characteristics of an electrically assisted turbofan engine

With the growing pressure to reduce the environmental footprint of aviation, new and efficient propulsion systems must be investigated. The current research looks at the operating characteristics of a turbofan engine in a parallel hybrid-electric propulsion system. Electric motors are used to supply power in the most demanding take-off and...

Verification of the ozone algorithmic climate change functions for predicting the short-term NOx effects from aviation en-route

For the first time, the algorithmic Climate Change Functions (aCCFs) for ozone, methane, water vapor, and persistent contrails have been developed within the ATM4E project to provide information on the climate sensitive regions, which can be conveniently implemented for the climate based flight routing. These aCCFs need to be verified before...

Multidisciplinary Collaboration Through Online Virtual Research Environments (VREs): What do VRE users need?

Making new data combinations and collaborating with researchers from different disciplines are becoming essential ingredients of scientific research. These activities are increasingly contributing to solutions for multidisciplinary global problems, such as climate change and energy transition. Virtual Research Environments (VREs) can potentially...

Open science, open government and open data: creating an impact through open online education and Virtual Research Environments

How to improve policy making using open data in Virtual Research Environments? An interactive workshop discussing privacy, security and trust strategies

Governments and publicly-funded research institutions increasingly open up data collected and created through research. One way to share and use data obtained through research is through Virtual Research Environments (VREs). Insights obtained through open data use in VREs can subsequently provide input for policy making. However, this process...

Hoplite - a conceptual design environment for helicopters incorporating morphing rotor technology

The SABRE project has been initiated under the EU’s Horizon 2020 programme for development of blade morphing technologies for helicopter rotors. The project targets reductions in fuel burn and NOx emissions of upto 5-10% through the use of morphing rotor blades. A new design tool for rotorcraft, HOPLITE, is being developed to investigate the...

Spectral Polarimetric Features Analysis of Wind Turbine Clutter in Weather Radar

Wind turbine clutter has gradually become a concern for the radar community for its increasing size and quantity worldwide. Based on the S-band polarimetric Doppler PARSAX radar measurements, this paper demonstrates the micro-Doppler features and spectral-polarimetric characteristic of wind turbine clutter, the probability distribution functions...

Polarimetric optimization for clutter suppression in spectral polarimetric weather radar

For the polarimetric-Doppler weather radar, sometimes there are artifacts caused by radar system itself or external sources displaying in the radar plan position indicator (PPI). These artifacts are not confined to specific range bins and also they are non-stationary when observed in the Doppler domain. This paper puts forward a method to...

Performance assessment of a Multi-fuel Hybrid Engine for Future Aircraft

This paper presents performance assessment of the proposed hybrid engine concept using Liquid Natural Gas (LNG) and kerosene. The multi-fuel hybrid engine is a new engine concept integrated with contra rotating fans, sequential dual combustion chambers to facilitate “Energy Mix” in aviation and a Cryogenic Bleed Air Cooling System (CBACS). The...

Using Open Research Data for Public Policy Making: Opportunities of Virtual Research Environments

Governments and publicly-funded research organisations increasingly make research data available openly. Researchers can use this data in Virtual Research Environments (VREs) to conduct multidisciplinary data-driven research and to obtain new insights potentially for governmental policy-making. However, the requirements for such a VRE are not...