ADVANCED TURBINE AERODYNAMIC DESIGN UTILIZING A FULL STAGE CFD

ABSTRACT Gas turbines for power generation are required to operate more efficiently than ever before for both economic and environmental reasons. Because of this situation, an advanced multistage turbine design and optimization system is required to improve upon existing turbine designs where viscous CFD codes had already been applied on a single row or single stages basis. An advanced CFD code for multistage design applications has been developed at Mitsubishi Heavy Industries (MHI) and has been applied to the redesign of a four stage single shaft turbine. The front 3 stages of the turbine are highly cooled using about 20% cooling air. The outstanding performance of this redesigned turbine has been demonstrated at MHI's engine test facility. This paper focuses on the customization of the Denton code [5] for industrial usage, the validation of the customized code employing experimental data, and finally the use of the code in executing a successful redesign. Code development and validation are discussed in terms of prediction accuracy for the basic aerodynamic design parameters such as exit flow angle and cascade losses. Through-flow design parameters such as pressure ratio and reaction of each stage are also addressed. Especially important in modern high temperature turbines is the location and distribution of cooling and leakage air being introduced into the main gas-path. The proper treatment of these flows is very important because of the mixing losses and the temperature migration downstream. These important considerations in any analysis approach are discussed and it is shown how they are treated in the customized CFD code. Consistency between the customized CFD code and other parts of the existing aerodynamic design procedure are carefully examined. This is important because aerodynamic parameters have different modeling fidelities in the different parts of the design system. Computer execution times are a very important consideration when utilizing advanced CFD codes. This issue is addressed from the perspective of an industrial design organization. In validating the customized code, special attention was placed on tip clearance leakage flow behavior and seal air migration from the hub wall. Local changes of total pressure and temperature distributions affect the local velocity triangles and local static pressure distributions on the airfoil and end-wall surfaces. Airfoil section geometry and three-dimensional stacking to maximize the turbine efficiency are also considered and discussed. The validated code was subsequently used to execute a redesign of a large frame industrial turbine. This is discussed in some detail. The redesigned turbine has completed full scale engine testing and has been shown to have met all design goals. The CFD predictions are compared with special measurements taken in the engine such as the inter-stage span-wise total pressure and temperature distributions as well as the efficiency trend versus engine load. These comparisons prove the capability of the advanced multistage CFD code. NOMENCLATURE Pt total pressure m mass flow rate specific heat ratio M Mach number T total temperature V velocity angle between main flow and seal air injection cool cooled turbine efficiency P turbine power subscripts actual actual work seal seal air gas main gas flow ideal isentropic work based on expansion ratio of each flo

A case of mediastinal goiter treated surgically using a clavicle-lifting technique

AbstractIntroductionMediastinal goiter is a benign disease, which is defined as a goiter with the greater portion of its mass lying below the thoracic inlet. It is controversial whether the cervical approach is the best approach for all mediastinal goiter surgeries.Case presentationA 71-year-old woman presented with respiratory discomfort during exertion. Computed tomography (CT) revealed a mediastinal goiter extending to the arch of the aorta. Surgical resection was performed using a clavicle-lifting technique. The excised specimen was 13×10×5cm in size and weighed 220g. The pathological diagnosis was nodular goiter.DiscussionThe clavicle-lifting technique is a simple and safe technique that involves lifting the clavicles with a pediatric extension retractor (Kent Retractor Set, Takasago Medical Industry, Tokyo, Japan). This is a good choice for surgery on upper mediastinal lesions such as mediastinal goiters as it obviates the need for a median sternotomy.ConclusionAlthough further study is necessary, it appears that a transcervical approach using the clavicle-lifting technique may be an acceptable treatment for mediastinal goiters that extend to the aortic arch

Synthesis and Evaluation of 1,3a,6a-triazapentalene (TAP)-bonded system

A method of synthesizing a directly connected 1,3a,6a-triazapentalene (TAP) ring system as a linearly bonded aromatic system with a planar form was established. Various TAP-dimers and a 2-alkyl-TAP-trimer were synthesized and their fluorescence properties were evaluated. Although the direct connection of the TAP ring with other TAP rings did not affect the fluorescence properties in diluted solvent, TAP-dimers showed unique fluorescence properties derived from the aggregation state under highly concentrated conditions. In particular, TAP-dimer 5f showed aggregation-induced emission in highly concentrated solution, and 5b showed typical mechanochromic fluorescence in the solid state despite their compact molecular size

Absence of in vivo selection for K13 mutations after artemether–lumefantrine treatment in Uganda

Additional file 1. Eligibility criteria for recruitment into the therapeutic efficacy study and the molecular study

ALK-Positive Squamous Cell Carcinoma Dramatically Responded to Alectinib

Anaplastic lymphoma kinase (ALK) rearrangement is usually observed in patients with adenocarcinoma. Herein, we report a case of squamous cell carcinoma (SCC) with ALK rearrangement treated with alectinib. The patient was a 73-year-old woman without a smoking history. She consulted us with nonproductive cough and loss of appetite. Computed tomography scan revealed a mass in the left lower lobe of the lung. According to the pathological examinations, we diagnosed the tumor as SCC. Because the patient had never smoked, we searched for driver mutations and found that the tumor harbored ALK rearrangement. We began treatment with alectinib, and the tumor remarkably reduced in volume. No severe adverse events were observed. Although there are only few reports of SCC with ALK rearrangement, this case implies that clinicians should consider searching for driver mutations in patients with SCC when there are atypical findings or characteristics

A ROENTGENOCEPHALOMETRIC STUDY ON THE POSITION OF THE HYOID BONE

The position of the hyoid bone as related to the cranial base and to the mandible was investigated. The materials used in this study were twenty Japanese adults of both sexes with normal occlusion, and twenty orthodontic cases with upper protrusion (Angle Class II division 1), and twenty lower protrusion cases (Angle Class III). The Hellman’s dental age analysis of these clinical cases was between III-C and IV-A. The position of the body of the hyoid as related to the cranial base showed a significant difference among· these three groups. Compared with the normal occlusion group, the body of the hyoid was located slightly backward in the upper protrusion group and slightly forward in the lower protrusion. However, in relation to the mandible, position of the body of the hyoid was constant in these three groups. In order to confirm the stability of the relative position of the hyoid to the mandible, following two cases were investigated; an ankylosis of the temporomandibular joint and a case of lower protrusion with severe distortion of the cervical vertebra caused by tuberculosis of spines. In the former case, the mandible was located far backward in relation to the cranium, while that of the latter was located far forward. However, the relative position of the hyoid to the mandible seemed to be stable in these two cases. The hyoid as related to the cranial base varied when the mandible took anteroposterior malpositions to the cranium. Considering the fact that the hyoid position as related to the mandible was stable, the muscles which connect them seemed to play an important role in the displacement of the mandible

Effect of Serum SPARC Levels on Survival in Patients with Digestive Tract Cancer: A Post Hoc Analysis of the AMATERASU Randomized Clinical Trial

Observational studies suggest that physical activity may improve, whereas sarcopenia may worsen the survival of cancer patients. It has been suggested that secreted protein acidic and rich in cysteine (SPARC), one of the myokines that is secreted into the bloodstream by muscle contraction, has tumor-suppressive effects. Based on the hypothesis that serum SPARC level may be a potential prognostic biomarker, a post hoc analysis of the AMATERASU randomized, double-blind, placebo-controlled trial of postoperative oral vitamin D supplementation (2000 IU/day) in patients with stage I–III digestive tract cancer from the esophagus to the rectum (UMIN000001977) was conducted with the aim of exploring the association between serum SPARC levels after operation and survival. On multivariate analyses adjusting serum 25-hydroxyvitamin D, vitamin D supplementation, sarcopenia, body mass index, age, sex, cancer loci, stage, and adjuvant chemotherapy, patients with SPARC levels lower than the median level had a significantly higher risk for death than those with higher levels (hazard ratio, 2.25; 95% confidence interval, 1.25–4.05; p = 0.007), whereas there were no significant associations with other outcomes including recurrence. However, on the same multivariate analyses, sarcopenia was not a risk factor for death and/or relapse. These results suggest that serum SPARC levels may be a potential biomarker for death but not cancer relapse

Numerical Thermal Comfort Analysis Using Combined Computer-Simulated Person with Clothing and Multi-Node Thermoregulation Model

To analyse the interaction between the indoor environment and the human body, various computer-simulated persons (CSP) which can treat specific characteristics of the human body have been suggested as a “digital twin” for experimental thermal manikin. However, previous studies simplified or ignored the reproduction of the clothing function. In this study, a digital twin based on ANDI thermal manikin integrated with a multi-node thermoregulation model was developed in a naked and clothed state. In addition, to validate the prediction accuracy of numerical thermoregulatory analysis coupled with CSPCFD simulation, the analysis results were compared with the experimental results using thermal manikin. The computational model was generated based on 3D scan data of ANDI manikin and clothe. Moreover, the user subroutine program for coupled simulation of CSP and Fiala thermoregulation model was developed and applied into CSP to estimate the heat generation by metabolism, heat transfer between layers and parts, and skin surface temperature. CFD analysis was performed using CSP under identical environmental condition with the experiment, by setting CFD boundary conditions based on the data measured in the experiment. Through a series of numerical analyses, we confirmed that the analysis result of CSP corresponds well with experimental results using thermal manikin