Gozdem Kilaz

Middle distillates hydrogen content via GC×GC-FID

Liquid transportation fuels in the middle distillate range contain thousands of hydrocarbons making the predictions and calculations of properties from composition a challenging process. We present a new approach of hydrogen content determination by comprehensive two-dimensional gas chromatography with flame ionization detector (GC×GC-FID) using a weighted average method. GC×GC-FID hydrogen determination precision was excellent (0.005 wt% repeatability). The method accuracy was evaluated by high-resolution nuclear magnetic resonance (NMR) technique, which is non-biased, measures the H signal directly and was independently validated by controls in the current study. The hydrogen content (in the range of 12.72-15.54 wt%) in 28 fuel samples were determined using GC×GC-FID. Results were within ± 2% of those obtained via NMR. Owing to the fact that NMR is accepted as an accurate technique for hydrogen content determination, the GC×GC method proposed in this study can be considered precise and accurate.

Alternative aviation fuels fire safety

F sprays are commonly produced by increasing the relative velocity between liquid and gaseous phases. Particle-ImageVelocimetry (PIV) is a well-established technique for velocity analysis in multi-phase flows. We can perform PIV by illuminating the particles with a short light pulse, typically a laser pulse, which produces a set of successive digital images. Then, image-processing functions correlate these images to produce velocity vector fields. However, there are many factors to be considered during PIV experiments, including the particle size, pulse-width of the fluid injector imaging angle, and the size of the interrogation window, amongst other factors. Planning ahead and understanding your experiment’s requirements could save valuable time and resources. In this paper, we present a few steps for researchers planning to perform PIV experiments in fluid sprays. We discuss factors that affect the quality of the vector field results. We also show the light-scattering (Mie scattering) efficiency of fluid particles and how it is affected by both average particle size and imaging angle. Then we present a case study of a VHS fuel injector for small rotary engines. We show the experimental setup, the analysis procedure, and the results of applying PIV on jet fuel sprays. Our results include vector fields of small droplets (less than 50 microns in diameter) produced by microPIV tracking technique and shadowgraph images.We present a phase-field model for fracture in Kirchoff-Love thin shells using the local maximumentropy (LME) meshfree method. Since the crack is a natural outcome of the analysis it does not require an explicit representation and tracking, which is advantage over techniques as the extended finite element method that requires tracking of the crack paths. The geometric description of the shell is based on statistical learning techniques that allow dealing with general point set surfaces avoiding a global parametrization, which can be applied to tackle surfaces of complex geometry and topology. We show the flexibility and robustness of the present methodology for two examples: plate in tension and a set of open connected pipes.T work presents the design of a circuit to capture the signal from the skin-like heart beat sensor and convert it to an electrical signal. The circuit is one part of the optical heart beat detection system which also includes the skin-like optical sensor array and the laser source and data processing unit. The circuit will be connected with the sensor array which will be able to detect the sensing signal at each element of the array. The sensor system could also be applied to contact form detection in other biomedical system. The sensing element of the sensor system is realized through the measurement of the change of the resistance. The circuit will power the circuit system with a sequence of pulses and the output is distinguishable corresponding to each pulse. The circuit can handle single input and multiple outputs. Testing results showed that the prototype of our circuit built on a breadboard can meet the design criteria with the defect of non-zero offset at the output when the circuit is not powered. Based on the breadboard circuit, the final circuit will be fabricated through CMOS technology on a 3 mm×3 mm silicon chip in order to accommodate the real application of the sensor.M dynamic assembly relationship seriously influences the reliability and work efficiency of complex machinery. To design a more reasonable mechanical dynamic assembly relationship involving multiply objects and multiply disciplines, a novel optimization method (called as SR-DCRSM) and a optimization model (multilayer model) are proposed for mechanical dynamic assembly reliability optimal design. The SR-DCRSM is developed by integrating Support Vector Machine Regression (SR) and Distributed Collaborative Response Surface Method (DCRSM). To validate the proposed approach and model, the reliability optimal design of gas turbine high pressure turbine Blade-Tip Radial Running Clearance (BTRRC), as a representative mechanical dynamic assembly relationship, was completed by considering nonlinear material parameters and dynamic heat load and mechanical load. The optimization results demonstrate that all optimal solutions satisfy the requirements of reliability optimal design of BTRRC and assembly objects, and the optimized BTTRC deformation is reduced by 10% approximately, which are promising to improve BTRRC design and control. As shown in the comparison of methods and model, the presented SR-DCRSM holds higher computational efficiency and precision, and the multilayer model possesses higher precision for mechanical dynamic assembly reliability optimal design. The presented efforts not only improve the performance and reliability of gas turbine, but also provide a promising approach and a valuable optimization model for mechanical dynamic assembly reliability optimal design. Besides, the present works enrich mechanical reliability design theory and method. J Aeronaut Aerospace Eng 2015, 4:2 http://dx.doi.org/10.4172/2168-9792.C1.011

Investigation of fatty acid methyl esters in jet fuel

Sustainable aviation fuels research has considerable momentum in efforts lead by government, academia and industry. Environmentally sound domestic fuels allow significant benefits, while also creating some challenges due to their novelty. One of these challenges is the cross contamination of fatty acid methyl esters (FAME) in biodiesel with jet fuels. It was suspected that sharing the same supply chain caused FAME to contaminate jet fuels which lead to aircraft malfunction. Consequently, in 2010, aero engine original equipment manufacturers (OEMs) mandated an immediate allowable limit of 5 ppm FAME in jet fuels. Civil Aviation Authority later increased the limit to 30 ppm (2012). This study finds that the presence of FAME in Jet-A at a much higher concentration of 2 vol% does not have an adverse impact on the ASTM D1655 specifications (2013). Therefore, it is recommended that the current limit of 30 ppm be revised.