Effect of Intentional Mistuning on Dynamic Characteristics of a Energy Turbomachine Bladed Disk

In this article the effect intentional mistuning of an axial turbomachine bladed disk has been analyzed in order to reduce forced response due to low-order engine excitation. The maximum value of forced response of turbomachine rotor’s blades with mistuning parameters is usually much more than the value of the tuned rotors. An increase level mistuning of this critical value actually leads to a decrease magnifications of the forced response. Thus, the actual work has been introducing some degree of intentional mistuning in the design to achieve these purposes. The effectiveness of intentional mistuning has been researched at the design stage of the bladed disk in the energy turbomachines, which is introduced into the rotor’s design by changing the nominal mass of the blades in harmonic models.

Mathematic modeling of a new inlay buoyancy artefact

The novel buoyancy artefact concept for the use in mass metrology enables the determination and correction of systematic air buoyancy effects caused by measurements outside a vacuum. In contrast to other buoyancy artefacts with a nominal mass of 1 kg, the new artefact, called inlay artefact, has a smaller volume resulting from an enclosed tungsten core. The theoretical design of the new artefact consists of dismountable discs with spherical distance pieces and a cylinder. This work focuses on the design and mathematical model considering limiting factors caused by the handling and the geometry of the comparators used.

Modernization of Centrifugal Chlorine Compressor

In this paper modernization of a three-stage chlorine centrifugal compressor, in which chlorine is pressurized has been described. Machine nominal mass flow has been increased by 20% and the pressure rise has remained almost unchanged. New construction concept has been chosen basing on analysis of different design variants. Calculations were conducted with one-dimensional method with usage of in-house developed code. Algorithms implemented to this program are based on empirical studies and wide experience in compressor modernization and design. Moreover, results of modified machine acceptance test results, which satisfies VDI norm 2045/ISO 5389 has been presented.

Measurement of uranium-236 in particles by secondary ion mass spectrometry

The determination of the relative isotopic abundance by secondary ion mass spectrometry of 236U in uranium-containing material is complicated by the presence of 235U1H+ ions at the same nominal mass as the uranium isotopic peak.