The aim of the study presented herein is to numerically predict the behaviour of the airflow around a flying military aircraft with an active intake in which the airflow may enter and travel all the way up to the Aerodynamic Interface Plane (AIP, the analytical interface between the inlet and engine). Computational Fluid Dynamics (CFD) is used as the basic tool. The geometry created consists of a full scale military aircraft exposed to different flight conditions. The flow results are mainly focused at the AIP since the present study is a part of a greater research effort to estimate how the airflow distortion induced to the engine's face due to the aircraft's flight attitude, affects the embedded gas turbine's performance. The obtained results were validated through a direct comparison against similar experimental ones, collected from a wind tunnel environment.

Military aircrafts are often subjected to severe flight maneuvers with high Angles-of -Attack (AOA) and Angles of Sideslip (AOSS). These flight attitudes induce non-uniform in flow conditions to their gas turbine engines which may include distortion of inlet total pressure and total temperature at the Aerodynamic Interface Plane (AIP). Operation of the downstream compression system with distorted inflow typically results in reduced aerodynamic performance, reduced stall margin, and increased blade stress levels. In the present study the steady state total pressure distortion induced to the Aerodynamic Interface Plane due to the aircraft’s flight attitude have been estimated in terms of distortion descriptors. The distorted conditions at the interface between the intake and the engine have been predicted by using Computational Fluid Dynamics (CFD), where 33 different aircraft flight attitudes have been tested. Based on the obtained results the effect of Angle-of-Attack (AOA) and Angle of Side Slip (AOSS) on the distortion descriptors have been studied. The results showed that the distortion effect becomes more pronounced whenever this specific airframe configuration is exposed to incoming flow with an AOSS. Among the tested cases, the greatest total pressure defect at the AIP in terms of difference from the average value and of circumferential extent was calculated for the flight attitudes of 0·35M flight with 0° AOA and 8° AOSS and 0·35M fight with 16° AOA and 16° AOSS.

Military aircraft are often subjected to severe flight maneuvers with high Angles of Attack (AOA) and Angles of Sideslip (AOSS). These flight attitudes induce non-uniformity in flow conditions to their gas turbine engines which may include distortion of inlet total pressure and total temperature at the Aerodynamic Interface Plane (AIP). Operation of the downstream engine's compression system may suffer reduced aerodynamic performance and stall margin, and increased blade stress levels. The present study presents a methodology of evaluating the effect of inlet flow distortion on the engine's fan stability. The flow distortion examined was induced to the AIP by means of changing the aircraft's flight attitude. The study is based on the steady state flow results from 27 different flight scenarios that have been simulated in CFD. As a baseline model geometry an airframe inspired by the General Dynamics/LMAERO F-16 aircraft was chosen, which has been exposed to subsonic incoming airflow with varying direction resembling thus different aircraft flight attitudes. The results are focused on the total pressure distribution on the engine's (AIP) face and how this is manifested at the operation of the fan. Based on the results, it was concluded that the distorted conditions cause a shift of the surge line on the fan map, with the amount of shift to be directly related to the severity of these distorted conditions. The most severe flight attitude in terms of total pressure distortion, among the tested ones, caused about 7% surge margin depletion comparing to the undistorted value.

A new discrete model is presented for the evaluation of the dynamic characteristics, i.e. eigenfrequencies and eigenmodes, of tanks of arbitrary shape and fill level. The accuracy and efficiency of the proposed methodology is demonstrated via a number of comparison studies. The above discrete model is combined with structural and soil simulation models for the efficient dynamic analysis of 3-D tanks under earthquake excitation. The obtained results are in excellent agreement to those obtained using detailed analytical and FEM models.

Internet applications have been extended to various aspects of everyday life and offer services of high reliability and security at relatively low cost. This project presents the design of a reliable, safe and secure software system for real time remote operation and monitoring of an aero gas turbine with utilisation of existing internet technology, whilst the gas turbine is installed in a remote test facility This project introduces a capability that allows remote and flexible operation of an aero gas turbine throughout the whole operational envelope, as required by the user at low cost, by exploiting the available Internet technology. Remote operation of the gas turbine can be combined with other remote Internet applications to provide very powerful gas turbine performance simulation experimental platforms and real time performance monitoring tools, whilst keeping the implementation cost at low levels. The gas turbine used in this experiment is an AMT Netherlands Olympus micro gas turbine and a spiral model approach was applied for the software. The whole process was driven by risk mitigation. The outcome is a fully functional software application that enables remote operation of the micro gas turbine whilst constantly monitors the performance of the engine according to basic gas turbine control theory. The application is very flexible, as it runs with no local installation requirements and includes provisions for expansion and collaboration with other online performance simulation and diagnostic tools.