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Recent advancements in electrified transportation have been necessitated by the need to reduce environmentally harmful emissions. Accordingly, several aviation organisations and governments have introduced stringent emission reduction targets for 2050. One of the most promising technologies proposed for achieving these targets is turboelectric distributed propulsion (TeDP). The objective of this study was to explore and identify key indicators for enhancing the applicability of TeDP in air transportation.

An enhancement valuation method was proposed to overcome the challenges associated with TeDP in terms of technological, economic and environmental impacts. The result indicators (RIs) were determined; the associated performance indicators (PIs) were analysed and the key RIs and PIs for TeDP were identified. Quantitative measurements were acquired from a simulated TeDP case study model to estimate the established key PIs.

It was determined that real-world TeDP efficiency could be enhanced by up to 8% by optimising the identified key PIs.

This study is the first to identify the key PIs of TeDP and to include a techno-economic environmental risk analysis (TERA) based on the identified key PIs. The findings could guide developers and researchers towards potential focus areas to realise the adoption of TeDP.

Centrifugal compressors are integral components in oil industry, thus effective maintenance is required. Condition-based maintenance and prognostics and health management (CBM/PHM) have been gaining popularity. CBM/PHM can also be performed remotely leading to e-maintenance. Its success depends on the quality of the data used for analysis and decision making. A major issue associated with it is the missing data. Their presence may compromise the information within a set, causing bias or misleading results. Addressing this matter is crucial. The purpose of this paper is to review and compare the most widely used imputation techniques in a case study using condition monitoring measurements from an operational industrial centrifugal compressor.

Brief overview and comparison of most widely used imputation techniques using a complete set with artificial missing values. They were tested regarding the effects of the amount, the location within the set and the variable containing the missing values.

Univariate and multivariate imputation techniques were compared, with the latter offering the smallest error levels. They seemed unaffected by the amount or location of the missing data although they were affected by the variable containing them.

During the analysis, it was assumed that at any time only one variable contained missing data. Further research is still required to address this point.

This study can serve as a guide for selecting the appropriate imputation method for missing values in centrifugal compressor condition monitoring data.

Describes a novel concept in aircraft propulsion: investigates a variable cycle jet engine for a supersonic advanced short take‐off vertical landing (ASTOVL) aircraft. The engine is the selective bleed turbofan. The selective bleed turbofan is a two shaft, three compressor, variable cycle gas turbine. At subsonic flight speeds it operates as a medium bypass turbofan. It becomes a low bypass turbofan when flying faster and is capable of supersonic cruise in the dry mode. A preliminary design of an ASTOVL aircraft from Cranfield, the S‐95, was used as the vehicle. Outlines the performance of the engine and its integration with the aircraft. Explains off‐design engine performance characteristics and describes variable geometry requirements. The major advantage of this engine is that all the components are employed all the time, for all operating modes, thus incurring low weight penalties. Predicts that the aircraft/ engine combination will perform in a satisfactory way, meeting most performance targets provided that some improvements are carried out.