PHITSコードとMKモデルを組み合わせたホウ素中性子捕捉療法における生物学的効果比の評価

この博士学位論文は学術雑誌掲載論文から構成されていますJournal of Radiation Research, 56(2), 382–390, https://doi.org/10.1093/jrr/rru109筑波大学 (University of Tsukuba)201

FEDSM2003-45101 STUDY ON PERFORMANCE AND INTERNAL FLOW OF CROSS FLOW WIND TURBINE

ABSTRACT The wind turbine has become more popular in recent years, but on the other hand, the developments of small wind-turbine have been legging behind. Because, the energy density of wind is small, since the efficiency of the main part of a wind turbine is very low. The construction costs become comparatively highpriced. Then, the main part of this subject is to show that, by collecting and sucking out more winds, a wind turbine is made to pass many winds and the new cross-flow wind turbine that increases an output coefficient is proposed. The cross-flow wind turbine has high torque and low speed characteristics and the structure are very simple. So, it can be used in a large wind velocity region. However, even if the power coefficient is high, it is about 10%. The purpose of this paper is to show how we can improve the power coefficient by applying a casing, which has a nozzle and a diffuser. This research was made to clear up fundamental characteristics of the interaction between outer flow and inner flow. Three kinds of cross-flow wind turbines were designed. The nozzle and diffuser have been designed suitable for the performance of wind turbine. The flow simulations by CFD have been carried out for various types of casings at 20 m/s with Fluent Ver5.0. All Wind tunnel experiments were performed at 20m/s. The case of casing 2, which have plate arranged near the separation point of cylinder, also experimented. The rotor that is settled in the casing 1 shows a larger power coefficient than the case without a casing. The casing of the cross-flow turbine makes a pressure difference between inflow and outflow. The pressure difference increases the mass flow rate. Therefore much more wind passes through into the cross-flow turbine. In this experiment, the power coefficient increased 1.5 times in the case with casing. A still higher output coefficient could be obtained in the case where it is shown by the casing 2

FEDSM2005-77387 STEADY ANALYSIS OF THERMODYNAMIC EFFECT OF PARTIAL CAVITATION USING SINGULARITY METHOD

ABSTRACT It is well known that the suction performance of turbopumps in cryogenic fluids is much better than that in cold water because of thermodynamic effect of cavitation. In the present study, an analytical method to simulate partially cavitating flow with the thermodynamic effect in a cascade is proposed; heat transfer between the cavity and the ambient fluid is modeled by one-dimensional unsteady heat conduction model under the slender body approximation and is coupled with a flow analysis using singularity methods. In this report, the steady analysis is performed and the results are compared with those of experiments to validate the model of the present analysis. This analysis can be easily extended into unsteady stability analysis for cavitation instabilities such as rotating cavitation and cavitation surge

Theoretical Analysis of Unsteady Blade Loading of Inducers Under Rotating Cavitation

Rotating cavitation is one of the flow instabilities associated with cavitation, which has been a problem for the development of turbopumps of liquid rocket engines since it causes super-synchronous shaft vibration. Recently, it is argued that rotating cavitation might also cause large repetitive stresses on blades. This paper describes about the theoretical prediction of unsteady blade forces on the cavitating inducer under rotating cavitation. Unsteady pressure distributions and a lift force for a 2-dimensitional flat plate cascade under rotating cavitation are calculated by using a linearized free streamline theory based on the unsteady closed cavity model and singularity method. Since the linearized calculation cannot predict the absolute magnitude of the fluctuations, the unsteady pressure distributions and resulting lift fluctuations are presented for a given magnitude of cavity length fluctuations