School of Electrical and Electronics Engineeringhttp://hdl.handle.net/123456789/9412022-12-05T19:22:17Z2022-12-05T19:22:17ZExperimental and Numerical Investigation into Turbulent High Reynolds Number Flows Through a Square Duct with 90-Degree Streamwise Curvature - II Numerical MethodsOndore, Faustinhttp://hdl.handle.net/123456789/13222015-07-13T12:48:24Z2015-07-13T00:00:00ZExperimental and Numerical Investigation into Turbulent High Reynolds Number Flows Through a Square Duct with 90-Degree Streamwise Curvature - II Numerical Methods
Ondore, Faustin
A square duct with a 90-degree streamwise curvature is representative of complex flow domains. Such flow domains are encountered in the designs of fluids engineering systems, especially in the aerospace turbo-machinery components.
Examples include the gas turbine engine axial compressor interstage spaces, where the rise in air pressure (and hence compressor efficiency) is dependent on suppression of turbulence.
In the case of the centrifugal compressor, pressure rise in the Ushaped diffuser assembly where the suppression of turbulence is critical to the attainable pressure ratio. The results obtained from numerical calculations are analysed and discussed along with the corresponding hot-wire measurements and flow visualization result
from a wind-tunnel of identical configuration. Calculations are implemented in four turbulent models, i.e. Standard k-e Module, Algebraic Stress Model (ASM), Non-linear Renormalization Group (RNG) - k-e Model and Differential Stress Model (DSM). The discretization up-winding scheme is the Quadratic Up-winding with
Interpolation Kinematics (QUICK). Two high Reynolds number turbulent flows are investigated, with mainstream velocities of 12.3 m/s and 20.4 m/s, representing Re=3.56x105 and Re=6.43x105 respectively. Generally strong correlation between theory and experimental data are recorded. Further, as reported in similar
studies, the turbulence modules that are formulated to account for turbulence anisotropy return results that more closely match experimental measurements. Uniquely for this configuration, a massive flow detachment is predicted along the convex wall at about the 90˚ position. Also, the core of the fluid flow is observed to
shift from the outer to the inner areas of the bend in proportion to the secondary (recirculating) flow generated by the bend.
2015-07-13T00:00:00ZDevelopment of a remote sensing methodology for analyzing shifting cultivation and grazing patterns in the semi-arid region of Kenya.Wayumba, GOhttp://hdl.handle.net/123456789/11112015-05-27T13:18:36Z1983-01-01T00:00:00ZDevelopment of a remote sensing methodology for analyzing shifting cultivation and grazing patterns in the semi-arid region of Kenya.
Wayumba, GO
1983-01-01T00:00:00ZParameter optimization in design of a rectangular microstrip patch antenna using adaptive neuro-fuzzy inference system techniqueRop, K.VKonditi, D.B.OOuma, H.AMusyoki, S.Mhttp://hdl.handle.net/123456789/11102015-05-26T16:21:23Z2012-01-01T00:00:00ZParameter optimization in design of a rectangular microstrip patch antenna using adaptive neuro-fuzzy inference system technique
Rop, K.V; Konditi, D.B.O; Ouma, H.A; Musyoki, S.M
Modern wireless system
s are placing greater
emphasis on antenna designs for future development in
communication technology becau
se the antenna is a key
element in the overall communication system. A
Microstrip Antenna is well suited for wireless
communication due to its light weight, low volume and
low profile planar configuration which can be easily
conformed to the host surface. In this paper, an
optimization method based on adaptive neuro-fuzzy
inference system (ANFIS) for determining the parameters
used in the design of a rectangular microstrip patch
antenna is presented. The ANFIS has the advantages of
expert knowledge of fuzzy inference system (FIS) and the
learning capability of artificia
l neural network (ANN). By
calculating and optimizing the patch dimensions and the
feed point of a rectangular microstrip antenna, this paper
shows that ANFIS produces good results that are in
agreement with Ansoft HFSS 13.0 simulation results.
2012-01-01T00:00:00ZTraffic Analysis in the Reduction of Power Consumption in Cellular Radio Access NetworkKimanthi, ShadrackKibet, P. LMusyoki, Shttp://hdl.handle.net/123456789/11092015-05-26T16:14:04Z2015-01-01T00:00:00ZTraffic Analysis in the Reduction of Power Consumption in Cellular Radio Access Network
Kimanthi, Shadrack; Kibet, P. L; Musyoki, S
All over the world cellular network communication has become an integral part of people’s lives. This has changed how people behave and their demand for connectivity is anywhere and anytime. Understanding the subscriber calling patterns and behaviour is very important when planning for the network resources and carrying out network design. Traffic analysis is carried and is aimed at improving Quality of Service, determining the busy hour, estimating subscriber traffic usage, determining the amount of capacity (channel) required to satisfy a given number of subscribers in a cell or network among other reasons. This paper investigates the telecommunication traffic of a selected region. An analysis of the subscriber calling pattern will be carried out and a solution will be proposed on how to reduce power consumption in the cellular
network based on traffic load.
2015-01-01T00:00:00Z