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Efficacy of Development Control as a Tool for Monitoring Building Developments in Kenya
Omollo, Wilfred Ochieng Korea Institute of Construction Engineering and Ma 2019 Journal of construction engineering and project ma Vol.9 No.1
This study examined the efficacy of development control in the monitoring of building developments in Kenya, a case study of Kisii Town. It focused on the extent to which the 1968 Building Code was enforced by the County Government of Kisii in an attempt to promote quality assurance. The target population comprised 7,430 residential developments from where a sample size of 364 was proportionately and randomly drawn. Research findings indicated that 39% of developers were unaware that their developments should have been inspected during construction. Similarly, awareness of building inspection significantly predicted if developers issued Notices of Inspection to the planning authority to facilitate inspections. Consequently, developers who were unaware that their building constructions required inspection were 99.9% less likely to issue such notices. Moreover, developers who did not obtain development permission were correspondingly 99.9% less likely to issue Inspection Notices. As a result, those who did not issue Notices of Inspection were 99.8% less likely to have their buildings inspected during construction due to lack of records indicating when such constructions had commenced. The study concludes that although the County Government of Kisii is lawfully mandated to monitor building developments in Kisii Town, the function is not well executed. This gap affords developers with an opportunity of not conforming to the approved building plans.
Use of Visual C++ program to generate Ramjet Simulation code
George Omollo Owino,Changduk Kong(공창덕) 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation To understand the diversity and applicability of this tool an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 iterated under the same input parameters. Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. C++ compiler was chosen as a tool of use due to its availability, ease of use, ability to compute functions faster and uniquely possible to make a stand alone GUI executable in DOS mode. The program is developed in such a way that given the ambient flight conditions, burner exit temperature and several geometry areas the program generates its own input values used in the succeeding stations. A close resemblance of output values that define performance and thermodynamic state of the engine was realized between GASTURB 9 and using this code made from C++ compiler.
Pressure Recovery in a Supersonic Ejector of a High Altitude Turbofan Engine Testing Chamber
Owino George Omollo,공창덕(Changduk Kong) 한국추진공학회 2010 한국추진공학회지 Vol.14 No.6
This research aims in finding a more optimal ejector size for evacuating engine exhaust gasses and 20% of the cell cooling air. The remaining 80% of cell cooling air pumped into the test chamber is separately exhausted from the test chamber via a discharge port fitted with flow control valves and vacuum pump. Unlike its predecessor this configuration utilizes a smaller capture area to improve pressure recovery. The modified ejector size has a diameter of 1100㎜ enough to evacuate 66㎏/s jet engine exhaust in addition to about 20%, 24㎏/s of the cell cooling air tapped from the sterling chamber. This configurations has an area ratio of the engine exit and ejector inlet of about 1.2. Simulation results of the proposed ejector configuration, indicates improved pressure recovery.
조지(Owino George Omollo),공창덕(Changduk Kong) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11
본 연구는 최소 압력 모사로 엔진 배기가스를 배출시키기 위한 최적 이젝터 크기를 결정하기 위한 것을 목적으로 한다. 실험 챔버로 유입되는 2차 냉각 공기는 유량제어 밸브들과 진공펌프가 장착된 배출구를 통해 엔진배기가스는 분리되어 배출된다. 기존 고도시험 장치와 달리, 본 연구에 제안한 형상은 기존 이젝터의 압력 회복을 개선한 좀 더 작은 포획 면적을 가진 배기 이젝트를 사용하면 가스에 스텔링 챔버로 부터 20% 냉각 공기를 부가하여 배출시키도록 크기가 정해진다. 제안된 형상은 벨마우스 이젝터와 엔진배기 출구의 면적비가 이론적으로 약 1.2를 갖는다. 제안된 형상의 혼합 공기 모사결과에 따르면 큰 에너지는 기존 시스템 비해 좀 더 개선된 압력 회복과 감소된 전력 소모를 같음을 확인하였다. This study aims at finding an optimal exhaust diffuser design of a high altitude testing chamber for a low bypass turbofan engine (F404-402) with thrust pound force of 17,700 and air mass flow rate of 66kg/s ejecting at a speed of Mach 1.66. The final proposed ejector size has better pressure recovery characteristics and targets to reduce operational cost at engine performance testing. Conventional high altitude test chamber layout was adopted and first drawn in two dimensions using Autocad software so as to determine the gas path, the ejector frontal size was then determined from gas dynamics equations considering traditional gas ejection method where both the engine exhaust and cell cooling air are exhausted via the ejector. Modification to a smaller ejector with an alternative secondary cell cooling exhaust port was then performed and modelled in 3D using Solid Works software.
스마투무인 항공기용 터보엔진(PW206C)의 장착성능에 관한 연구
공창덕,George Omollo Owino 朝鮮大學校 機械技術硏究所 2006 機械技術硏究 Vol.9 No.1
The purpose of this study is to analyze both the design and off design performance simulation of the PW206C turbo shaft engine used in the development of the smart UAV (Unmanned Ariel Vehicle) by KARI(Korean Aerospace Research Institute). Its mainly aims to investigate performance behavior at the uri-installed and installed conditions. The ways employed to be able to analyze the performance extensively were mainly carried out by comparison of performance simulation results from both the commercial program 'GASTURB 9' using compressor maps generated by Genetic algorithms (GAs) or Scaling Method, and the engine manufacturer's program 'EEPP'. Off-design performance analysis was performed through matching of both mass flow and work between engine components. The set of performance simulations of the developed analytical models was performed by a commercial program package (GASTURB9) that provides great flexibility in the choice of independent variables of the overall system. The results from the simulations are used to compare turbo shaft engine (PW206C) performance data obtained by the EEPP. At uri-installed condition, it was found that the results with the compressor map generated by GAs were relatively agreed well than those with the compressor map generated by the Scaling Method. The performance calculation results using the compressor map generated by GAs were compared at uri-installed condition and installed conditions with ECS-off and ECS-Max in variation of altitude, gas generator speed and flight speed.
Visual C++프로그램을 이용한 Ramjet Simulation Code의 생성방법
공창덕(Changduk Kong),George Omollo Owino 한국추진공학회 2008 한국추진공학회 학술대회논문집 Vol.2008 No.5
본 연구에서는 Visual C++프로그램을 이용하여 램젯엔진시뮬레이션을 위한 코드를 생성하였다. 연구에 사용되어진 램젯엔진은 이상적인모델로 가정하였다. 우선, Visual C++에의해 만들어진 GUI프로그램을 이해하기위해 기초이론을 설명하였다. 주변에서 흔히 구할수 있고, 사용이 용이하며, 빠른계산이 가능한 Visual C++프로그램은 특히 GUI프로그램을 DOS Mode에서도 사용할 수 있게 해준다. GUI프로그램은 엔진흡입구의 초기입력값만 넣어주면, 나머지 스테이션의 초기입력값은 이 프로그램에 의하여 자동으로 계산되어진다. 이 프로그램의 결과는 널리사용되어지고 있는 상형툴인 GASTURB9의 결과와 비교하여 타당성을 검증하였다. This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. The program is designed that it generates its station input value. Similar results were realized compared to those produced by gasturb 9.