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In the past, the suspended sediment concentration (SSC) was mainly measured by the optical backscattering device (OBS) and water sample filtration. However, there has been a new development that user is based on the acoustics backscattering (ABS) to measure the SSC in the world. The acoustic instruments have some advantages that the optical ones do not have. For example, acoustic instruments are not effected by high turbidity, biofouling and high viscosity in the water. Acoustic instruments have high spatial and temporal resolutions. And they can immediately indicate the SSC changes than the water sample filtration method. Therefore, in this study we used the multi-frequency acoustics instrument (AQUAscat-1000) to investigate the relations of the suspended sediment size and concentration to the acoustic characteristics. The results are separated into two parts: (1) The calibration process in the flume. (2) The acoustic results in the field experiment. In the first part, we examined the range of preferred bin size with respect to the different frequencies as well as the condition in the flume, and determine that conclude the 20 mm is the best range for our case. In addition, the gain should be used when the maximum SSC is less than 100 mg/l and vice versa. Therefore, in the field case around the river mouth, the signal gain should be turned off due to high concentrations. According to the sensitivity of the backscatter intensity of different frequencies to the suspended particle sizes, multiple frequencies are needed to derive the SSC when the sediment size becomes smaller. The last point in this part is the comparison of the results between the acoustics and optical instruments. When the suspended particles in the water column are transparent, the optical measurement of the SSC is underestimated, but the acoustic method is not. The result of the field experiment in 2009 showed that the AQUAscat-1000 is a better instrument to quantify SSC than the optical instruments. The SSC increase caused by the bottom sediment re-suspension was due to the wave shear. In the 2011 experiment, although the acoustic results overestimated the SSC at some points but they still had higher relation and significance with water sample data than the optical measurements. The SSC increase caused by the bottom sediment re-suspension was due to the current shear.

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The diploma thesis addresses the topic of optical measurements of flange joints during tightening and thermal loading. Commercially available optical systems with decreasing invasiveness were compared in opportunity which offer to an industrial environment. Various conditions are evaluated in 3D (scanning, DIC) as well as in 2D (DIC). The data for evaluation of sensitivity and system accuracy together with the evaluation of the data range were obtained by the measurement. Data evaluation showed the same accuracy for 2D and 3D system and the possibility of quality inspection of the joint by assessing the inspection dimensions in operation.

The graduation thesis deals with invention of detailed definition of the coordinate system for Pontos system. The solution is based on suitable localization method of the point on a car body, whose coordinates are known from CAD data. First part of the thesis describes the design of adapter which determines the reference point. Software solution is presented in second part. Contribution of the work and accuracy of the method are discussed in the end.

<p> Understanding boundary layer transition is fundamental to hypersonic vehicle design as the significant heating induced by the transition process informs the development of vehicle thermal protection systems. Carbon-based thermal protection systems have been shown to decrease thermal loads and delay transition by absorbing thermal energy during ablative mass transfer into the boundary layer. To better understand this process, a high-repetition rate measurement technique is needed to temporally resolve carbon species concentrations as they propagate through the boundary layer at frequencies where boundary layer instabilities occur. Carbon monoxide is a dominant product from the chemical reactions that take place during the ablation process and is the species of interest considered in this work. A proposed approach is applying carbon monoxide two-photon laser-induced fluorescence (CO TP-LIF) at 100 kHz+ during a simulated ablation experiment where CO is injected into the boundary layer of an axisymmetric slender-body cone model in the Boeing/AFOSR Mach 6 Quiet Tunnel (BAM6QT) at Purdue University. To develop this capability, a custom-built optical parametric oscillator (OPO) was designed and used in conjunction with a burst-mode laser system to achieve narrowband excitation of CO at 100 kHz. The OPO was designed, built, and characterized through measurements of cavity energy efficiency, spectral bandwidth, and beam quality. Initial demonstrations to show the OPO could successfully achieve CO LIF were conducted in a vacuum cell at 10 Hz. The feasibility of performing CO LIF at 100 kHz in the BAM6QT was then assessed on a bench-scale using a burst-mode laser, a high speed camera, and an imaging intensifier. CO number densities in a vacuum cell were related to those that would be expected within the boundary layer of a 3 degree half-angle cone in the BAM6QT, and a series of measurements were made at these representative conditions. Appreciable signal levels were attained for single dimensional focused line measurements demonstrating high potential for using this technique in the BAM6QT at 100 kHz. The potential for a two-dimensional planar measurement was also assessed with decent promise for success for planar laser sheets of small dimensions (2 mm tall or less). Additionally, an initial BAM6QT test entry was carried out to gain experience with experimental setup; lessons learned from this experience are examined and discussed. To date, CO TP-LIF has only been applied up to 1 kHz repetition rates. This work represents a 100 fold increase over the current CO LIF state of the art and the first reported measurements, bench scale or otherwise, of 100 kHz-rate CO LIF. This lays the foundation for future CO LIF experiments in the BAM6QT at kHz-MHz repetition rates. </p>

With increasing global power demands, there is a growing need for the clean and efficient use of fossil fuel resources. Gas turbine engines are a commonly used means for generating power; from the propulsion of aircraft to electricity on municipal grids. Measuring the temperature within a turbine combustor or at a turbine inlet could provide numerous advantages related to engine control, durability, efficiency, and emissions and yet this relatively straightforward task has eluded turbine engine manufacturers, primarily because of the high temperatures and pressures, harsh environment, and limited access. Optical emissions measurements are of particular interest for this task as they only require one optical access point and can be accomplished using thin optical fibers that can be fit within existing turbine geometries.This work extends an optical emission method known as the integrated spectral band ratio (ISBR) method beyond previously obtained temperature measurements on atmospheric combustion products to temperature measurements in a pressurized turbine combustor. The ISBR correlates modeled integrated spectral band ratios of spectral water emission to gas temperature, comparable to two-color pyrometry. When the integrated spectral bands are measured, the temperature can be inferred from this correlation. This technique has previously been successfully applied at atmospheric conditions over pathlengths as short at 25 cm but in this case has been applied at pressures of 0.7 and 1.2 MPa and a pathlength of 15 cm.Optical measurements were taken in a pressurized combustion test rig at Solar Turbines Inc. in San Diego California. Two temperature sweeps at high load and low load (pressures of 1.2 and 0.7 MPa, respectively) were measured. The average ISBR optical temperature measurements were approximately 200 K higher than the downstream thermocouple measurements. Thermocouple radiative losses were predicted to yield a bias of -175 K. The slope of a change in optical temperature to change in thermocouple temperature was 1.03 over the 87 K variation seen. Repeatability of the optical measurement at a given operating condition was on the order of ± 15 K and the absolute uncertainty of a single measurement was estimated to be ± 70 K over a temperature range of 1350 to 1500 K. The spectra, measured with a Fourier Transform Infrared Spectrometer (FTIR), was in very good agreement with spectral emission models produced using a derivative of the HITEMP database. All of the measured peak locations matched the model, and the measured data matched changes in spectral wings with changing pressure. A linear correlation was also found between raw optical signal and thermocouple measurements.

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