Felix Johannes Förster

Felix Johannes Förster
University of Oxford | OX · Department of Physics

Dr.-Ing.

About

23
Publications
1,995
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
164
Citations
Introduction
Felix Johannes Förster currently works at the Department of Physics, University of Oxford. Felix does research in Aerospace Engineering and Optical Diagnostics.

Publications

Publications (23)
Article
The present work provides an overview on the possible phase transitions associated with supercritical fluid injection and a detailed evaluation of the mixing process between injectant fluid and quiescent ambience. The experiments cover superheated liquid disintegration, pseudo-boiling transition and single-phase jets under different nozzle pressure...
Article
Full-text available
Crank angle-resolved temperatures have been measured using laser induced grating spectroscopy (LIGS) in a motored reciprocating compression machine to simulate diesel engine operating conditions. A portable LIGS system based on a pulsed Nd:YAG laser, fundamental emission at 1064 nm and the fourth harmonic at 266 nm, was used with a c.w. diode-pumpe...
Conference Paper
Full-text available
A new reflected shock tube facility, the Cold Driven Shock Tube (CDST), has been designed, built and commissioned at the University of Oxford for investigating IC engine fuel spray physics and chemistry. Fuel spray and chemical kinetics research requires its test gas to be at engine representative pressures and temperatures. A reflected shock tube...
Article
Full-text available
We report a comprehensive speed of sound database for multi-component mixing of underexpanded fuel jets with real gas expansion. The paper presents several reference test cases with well-defined experimental conditions providing quantitative data for validation of computational simulations. Two injectant fluids, fundamentally different with respect...
Article
A novel manufacturing process for surface-integrated thermocouples is presented and its potential for heat transfer experiments is demonstrated. The presented manufacturing approach allows finely structured and reproducible thermocouples produced as part of the object under study. Therefore a fine channel is milled inside the investigated Perspex w...
Article
This study is the first to provide a comprehensive speed of sound database for multi-component jet mixing at high pressure. It serves as a unique reference for numerical simulations of mixture preparation processes in future liquid rocket engines and internal combustion engines. We performed quantitative speed of sound measurements in jet mixing zo...
Chapter
A detailed understanding of supersonic free jets and the underlying flow phenomena is key to many technical applications such as exhaust nozzle flows of aircraft or rocket engines, or for well-defined test cases in the validation process of numerical setups. In this paper, we suggest an uncooled, low-cost pitot probe made from a high perfomance met...
Chapter
Schlieren imagining is an often used technique to visualize shock and expansion waves in supersonic flows. While a conventional setup is sensitive to the entire light path between the imaging optics, the focusing Schlieren setup allows to select a specific focal plane normal to the optical axis for imaging due to its narrow depth of focus. In this...
Article
Full-text available
Thermometry using laser-induced grating spectroscopy (LIGS) is reported using a high-repetition rate laser system, extending the technique to allow time-resolved measurements of gas dynamics. LIGS signals were generated using the second harmonic output at 532 nm of a commercially available high-repetition rate Nd:YAG laser with nitrogen dioxide as...
Article
In this paper, we present a combined experimental and numerical approach to assess the thermal loads and the cooling mechanism of an internally cooled strut injector for a supersonic combustion ramjet. Infrared measurements of the injector surface are conducted at a moderate external flow temperature. In addition, the main flow field is investigate...
Conference Paper
Time- and space-resolved measurements of temperature and pressure in flames and engines using laser induced grating scattering from fuels, tracer species and combustion products are reported with precisions in the range 0.1-3%.
Article
Full-text available
The four-wave mixing technique laser-induced thermal acoustics was used to measure the local speed of sound in the farfield zone of extremely underexpanded jets. N-hexane at supercritical injection temperature and pressure (supercritical reservoir condition) was injected into quiescent subcritical nitrogen (with respect to the injectant). The techn...
Article
The scramjet engine is a promising propulsion concept for future space transportation systems. To enhance the engine efficiency, a strong understanding of combustion mechanisms is essential. Laser-induced thermal acoustics (LITA) – a seedless, non-intrusive measurement technique – is an auspicious technique for the investigation of supersonic combu...
Article
We conducted a comprehensive set of combustion experiments in a connected tube test facility to investigate the interface between supersonic and dual-mode combustion in a scramjet combustor. This is achieved using a staged injection scheme consisting of a strut as first stage and wall ramps as second stage. Wall pressure measurements, flame visuali...
Article
Full-text available
Non-resonant laser-induced thermal acoustics (LITA), a four-wave mixing technique, was applied to post-shock flows within a shock tube. Simultaneous single-shot determination of temperature, speed of sound and flow velocity behind incident and reflected shock waves at different pressure and temperature levels are presented. Measurements were perfor...
Conference Paper
An internally cooled central strut injector for SCRamjet application is investigated experimentally using infrared thermography. In addition to the experiments a fully coupled numerical simulation is conducted to enable a more detailed identification of main flow phenomena and their impact on the injector. Main features of the flow around the injec...
Conference Paper
Laser-Induced Thermal Acoustics (LITA), a seedless, non-intrusive measurement technique, is a promising tool for the investigation of supersonic flow and combustion diagnostics. In this paper, a heterodyne LITA setup is used for simultaneous measurements of the flow velocity and local speed of sound at discrete points in the flow field. The Mach nu...
Conference Paper
For supersonic combustion, data acquisition is a challenging task, but vital for CFD code validation. In this paper we present the seedless, non-intrusive measurement technique Laser-induced Thermal Acoustics (LITA) as promising alternative to established techniques. The requirements for LITA for measurements in ducted flows were identified. Furthe...
Conference Paper
Transient heating and pressurization of a gas by shock waves can be useful for a variety of purposes, particularly for configurations involving shock wave focussing. Unless the geometry is particularly simple, the time history of temperature can be difficult to predict accurately. Hence, a non-intrusive measurement technique with high temporal reso...
Conference Paper
For supersonic combustion, data acquisition is a challenging task, but vital for CFD code validation. The seedless, non-intrusive technique Laser-induced Thermal Acoustics (LITA) is a promising alternative to established techniques such as Particle Image Velocimetry (PIV) and Coherent anti-Stokes Raman Spectroscopy (CARS). In this paper, we present...
Article
Full-text available
Data acquisition in experiments is a challenging task especially for supersonic combustion but vital for CFD code validation. The seedless, non-intrusive technique Laser-induced Thermal Acoustics (LITA) is a promising alternative to established techniques such as Particle Image Velocimetry (PIV) and Coherent Anti-Stokes Raman Spectroscopy (CARS). I...
Conference Paper
This paper describes investigations into unsteady flow phenomena in a high turning linear cascade with a nominal steady flow. A fast response five hole probe was used to obtain time-accurate measurements. Since a single probe was used to traverse an entire measurement plane, the results were obtained as discrete points and were not synchronous. One...
Conference Paper
This paper describes investigations into unsteady flow phenomena in a high turning linear cascade with a nominal steady flow. Traditionally time averaged instrumentation is used in such a cascade. Detailed intermittency readings were taken inside the cascade using hot wires to highlight the detailed flow interactions of the passage vortex and the b...

Network

Cited By