With the growth of aviation traffic and demand for emission reduction, alternative fuels like so-called electrofuels could comprise a sustainable solution. Electrofuels are understood as those that use renewable energy fuel synthesis carbon-neutral with respect to greenhouse gas emission. In this study, five potential discussed application fuels, being n-octane, methanol, methane, hydrogen ammonia, compared conventional Jet A-1 fuel. Three important aspects illuminated. Firstly, process...

During the prototype shop tests, Model V84.3A ring combustor gas turbine unexpectedly exhibited a noticeable “humming” caused by self-excited flame vibrations in combustion chamber for certain operating conditions. The amplitudes of pressure fluctuations were unusually high when compared to previous experience with silo machines. As part optimization program, humming was investigated and analyzed. To date, instabilities real, complex combustors cannot be predicted analytically during design...

The main contributing factors to unsteady loading of Offshore Wind Turbines (OWT) are wind shear, turbulence, and waves. In the present paper, turbulence intensity shear exponent investigated. Using data from FINO 1 research platform, these parameters analyzed compared with proposed field in IEC standard 61400-3. Based on this analysis, aeroelastic simulations performed determine effect fatigue extreme loads rotor blades. For investigations, model a 5 MW OWT is used focus design load cases...

The regeneration process of jet engines is a highly complex, expensive and time-consuming. Especially the high pressure turbine blades compressor blisks are at border what technically feasible. These components loaded thus substantial wear occurs. must be overhauled or replaced regularly. existing repair methods for these parts inflexible cannot applied in many cases, resulting large number scrapped parts. Therefore new blade presented. goal improved to reduce scrap rate cost. This includes...

Nonharmonic acoustic resonance was detected in the static pressure and sound signals a four-stage high-speed axial compressor when operating close to surge limit. Based on prior research reported literature measurements of frequency, Mach number mean flow, circumferential phase shifts signal during resonance, it is shown that an standing wave spinning mode with three periods around circumference compressor. This phenomenon occurs only if aerodynamic load high, because needs high for...

The surface topography of milled workpieces often defines their performance. One example is blades in turbine engines, where the flow losses. This type complex goods machined by ball end mills, either for manufacture or repair. literature offers various model types to predict order design a machining process without prior experiment. most accurate models use real kinematics and blend tool with workpiece. But this prediction ignores differences between reality simulation due vibrations,...

Optical full-field measurement methods such as Digital Image Correlation (DIC) provide a new opportunity for measuring deformations and vibrations with high spatial temporal resolution. However, application to full-scale wind turbines is not trivial. Elaborate preparation of the experiment vital sophisticated post processing DIC results essential. In present study, rotor blade 3.2 MW turbine equipped random black-and-white dot pattern at four different radial positions. Two cameras are...

In centrifugal compressors, variable inlet guide vanes (IGVs) are used to control the mass flow rate with negligible change in pressure ratio and shaft speed. The efficient operation of IGVs is limited range aerodynamic stability their vane profiles. Thin symmetric profiles, which usually used, tend exhibit separation already at low setting angles, resulting a rapid decrease global efficiency. Three different including reference profile, two-piece tandem profile angle, an s-cambered together...

The length of wind turbine rotor blades has been increased during the last decades. Higher stresses arise especially at blade root because longer lever arm. One way to reduce unsteady blade-root caused by turbulence, gusts, or shear is actively control lift in tip region. promising method involves airfoils with morphing trailing edges and consequently loads acting on blade. In present study, steady behavior an airfoil a edge investigated. Two-dimensional Reynolds-Averaged Navier-Stokes...

Turbocharger performance significantly affects the thermodynamic properties of working fluid at engine boundaries and hence performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat power produced by turbine, consumed compressor, volumetric efficiency. Therefore, non-adiabatic can restrict charging process The present research work investigates effect on turbo lag. Two passenger car turbochargers are experimentally theoretically investigated....

Abstract. This study shows an extensive analysis of dynamic stall on wind turbine airfoils, preparing for the development a reduced-order model applicable to thick airfoils (t/c>0.21) in future. Utilizing unsteady Reynolds-averaged Navier–Stokes (URANS) simulations pitching FFA-W3-211 airfoil with Reynolds number 15 × 106, our identifies distinct phases course evolution stall. While is conventionally categorized into primary-instability transitioning vortex formation stage, we suggest two...

The FVV-sponsored-Project “Bow Blading” (c.f. acknowledgments) at the Turbomachinery Laboratory of University Hannover addresses effect strongly bowed stator vanes on flow field in an 4-stage high speed axial compressor with controlled diffusion airfoil (CDA) blading. is equipped more than have previously been reported literature. performance map present being investigated experimentally and numerically. results show that pressure ratio efficiency design point choke limit are reduced by...

During the last decades, riblets have shown a potential for viscous drag reduction in turbulent boundary layers. Several investigations and measurements of skin-friction layer over flat plates on turbomachinery-type blades with ideal riblet geometry been reported literature. The question where must be applied surface compressor blade is still not sufficiently answered. In first step, profile loss by triangular trapezoidal groove constant along suction pressure sides investigated. results...

Abstract Shape adaption (SA) via piezo-ceramic actuation, and active flow control (AFC) by means of fluid injection aspiration, are investigated within the Cluster Excellence for Sustainable Energy-Efficient Aviation (SE 2 A) with goal increasing efficiency multi-stage compressors—particularly at part-load, extending their operating range. Although both technologies have shown to be beneficial compressor off-design operation, drawbacks still apparent aerodynamic design point when a single...

The FVV sponsored project “Bow Blading” (cf. acknowledgments) at the Turbomachinery Laboratory of University Hannover addresses effect strongly bowed stator vanes on flow field in a four-stage high-speed axial compressor with controlled diffusion airfoil (CDA) blading. is equipped more than have previously been reported literature. performance map present being investigated experimentally and numerically. results show that pressure ratio efficiency design point choke limit are reduced by...

The correct prediction of the temperature distribution is a prerequisite for reliable determination species and current distributions in any solid oxide fuel cell (SOFC) model. It even more crucial if model intended analysis thermo-mechanical stresses. This paper addresses different mechanisms heat generation absorption cell. Particular attention paid to heating associated with oxidation hydrogen, which commonly assigned interface between electrolyte anode SOFC modeling. However, detailed...

In centrifugal compressors, variable inlet guide vanes (IGVs) are used to control the mass flow rate with negligible change in pressure ratio and shaft speed. The efficient operation of IGVs is limited range aerodynamic stability their vane profiles. Thin symmetric profiles, which usually used, tend exhibit separation already at low setting angles, resulting a rapid decrease global efficiency. Three different profiles including reference, two-piece tandem profile angle, an s-cambered,...

Since Oehlert et al. (2007, “Exploratory Experiments on Machined Riblets for 2-D Compressor Blades,” Proceedings of International Mechanical Engineering Conference and Exposition 2007, Seattle, WA, IMECE2007-43457), significant improvements in the manufacturing processes riblets by laser structuring grinding have been achieved. In present study, strategies small-scale grooves with a spacing smaller than 40 μm metal bonded wheels are presented. For laser-structuring process, production time...