• Title/Summary/Keyword: Transient Performance Analysis

Search Result 562, Processing Time 0.018 seconds

Optimal arrangement of multiple wind turbines on an offshore wind-wave floating platform for reducing wake effects and maximizing annual energy production (다수 풍력터빈의 후류영향 최소화 및 연간발전량 극대화를 위한 부유식 파력-해상풍력 플랫폼 최적배치)

  • Kim, Jong-Hwa;Jung, Ji-Hyun;Kim, Bum-Suk
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.41 no.3
    • /
    • pp.209-215
    • /
    • 2017
  • A large floating offshore wind-wave hybrid power generation system with an area of 150 m2 and four 3 MW class wind turbine generators was installed at each column top. In accordance with the wind turbine arrangement, the wake generated from upstream turbines can adversely affect the power performance and load characteristics of downstream turbines. Therefore, an optimal arrangement design, obtained through a detailed flow analysis focusing on wake interference, is necessary. In this study, to determine the power characteristics and annual energy production (AEP) of individual wind turbines, transient computational fluid dynamics, considering wind velocity variation (8 m/s, 11.7 m/s, 19 m/s, and 25 m/s), was conducted under different platform conditions ($0^{\circ}$, $22.5^{\circ}$, and $45^{\circ}$). The AEP was calculated using a Rayleigh distribution, depending on the wind turbine arrangement. In addition, we suggested an optimal arrangement design to minimize wake losses, based on the AEP.

The Results of Radiation Therapy of Limited Stage Small Cell Lung Cancer (국한된 페소세포암의 방사선 치료성적)

  • Kim Sung Hwan;Choi Byung Ok;Gil Hak Joon;Yoon Sei Chul;Bahk Yong Whee;Shinn Kyung Sub;Kim Hoon Kyo;Lee Kyung Sik
    • Radiation Oncology Journal
    • /
    • v.11 no.1
    • /
    • pp.97-102
    • /
    • 1993
  • A retrospective analysis of various characteristics in 32 limited stage small cell lung cancer patients treated at the Department of Therapeutic Radiology in Kangnam St. Mary's Hospital, Catholic University Medical College from April 1983 to September 1991, was carried out to identify factors which had prognostic significance for survival from initiation of radiation therapy. There were 26 men and 6 women. Median age was 63 years (range: 24-78 years). The follow up duration was 1.5 to 44 months (median: 9 months). External radiation therapy was done with daily 160-180 cGy,5 fraction/week, total of 1000-6660 cGy (median: 4500 cGy) to the mediastinum by 6 MV linear accelerator. Of 32 Patients, 27 ($84.4{\%}$) patients were treated with combined modality (chemotherapy plus radiation therapy), and 5 ($15.6{\%}$) patients were treated with radiation therapy only. Complete responders were 12 patients ($37.5{\%}$), partial responders were 11 ($34.4{\%}$), and no responders were 9($28.1{\%}$). Karnofsky performance status over 70 (p<0.04), chemotherapy regimen (CAV, PV, and CAV+PV) (p<0.04),6 or more cycles of chemotherapy (p<0.007), radiation therapy over 4500 cGy (p<0.03), and radiation therapy responder (CR+PR) (p<0.003) showed a significantly favorable influence on 1 year survival rate. Age (p=0.545), sex (p=0.666), presence of superior vena cava syndrome (p=0.719), prophylactic cranial irradiation (p=0.217), and radiation therapy duration (p=0.491) had no effect on survival. Radiation induced side effects were transient esophagitis in 11 ($34{\%}$), general weakness in 9($28{\%}$), gastrointestinal symptoms in terms of nausea, vomiting and indigestion in 5 ($15{\%}$) and leukopenia in 1 ($3{\%}$).

  • PDF