Aerospace EngineeringThis collection contains research work by Aerospace Engineering Students at master's Level from 2021- 2022http://repository.aust.edu.ng/xmlui/handle/123456789/50742024-03-29T09:57:23Z2024-03-29T09:57:23ZParametric Analysis of a Convergent-Divergent Nozzle for 2N Cold Gas Propulsion of a NanosatelliteIbrahim, Jemila Jummaihttp://repository.aust.edu.ng/xmlui/handle/123456789/50872022-08-31T21:00:44Z2021-09-09T00:00:00ZParametric Analysis of a Convergent-Divergent Nozzle for 2N Cold Gas Propulsion of a Nanosatellite
Ibrahim, Jemila Jummai
In recent times, the concepts of microsatellite development have been a versatile subject ranging from their ability to reduce overall cost of satellites to their improved efficiency and adaptability. This has brought new innovations about creating micro-components for the satellite missions. The study of convergent-divergent (C-D) nozzle is an ever-growing research area due to its wide applications particularly in the aerospace field. Hence, this research study particularly looks into studying the influence of varying divergence angle and divergence length on flow parameters for optimum nozzle design. Propellant selection criteria were drawn up for cold gaseous propellants to test their effectiveness leading to the choice of compressed air and Nitrogen as preferred propellants due to their availability, inertness and non-toxicity. Varying the divergence angle of a C-D nozzle produced a series of nozzle geometries and the analysis of simulation results yielded an optimum angle of 15° with choking effect at the throat located at 0.3m. Other divergence angles considered including 5°, 10°, 20°, 25° and 30o generated multiple shocks across the nozzle throat. A divergence length of
1.35m produced the highest exit pressure of 61.756kPa close to ambient pressure. Divergence length of 1.35m coupled with a divergence angle of 15° appears to be most appropriate for the design of a C-D nozzle suitable for microsatellite propulsion system.
2021 Aerospace Engineering Masters Theses
2021-09-09T00:00:00ZDesign and Analysis of C-Band Microstrip Patch Antenna for Satellite CommunicationIkwunne, Chineye Ndidiamakahttp://repository.aust.edu.ng/xmlui/handle/123456789/50862022-08-31T21:00:42Z2021-09-01T00:00:00ZDesign and Analysis of C-Band Microstrip Patch Antenna for Satellite Communication
Ikwunne, Chineye Ndidiamaka
Low gain and narrow bandwidth associated with microstrip patch antennas for satellite application is studied in this submission. Evaluation of the best feed technique with insertand edge using HFSS software was done with the aim of improving bandwidth and gain. The designed co-polanar waveguide (CPW) antenna utilized Flame Retardent - 4 epoxy of 1.6 mm thickness and dielectric constant of 4.4 as substrate, which gave a simulated return loss value of less than -10dB, gain of 4.2 dB and an improved bandwidth of 3.5 GHz.The designed antenna is suitable for satellite communication, military and other wide band applications.
2021 Aerospace Engineering Masters Theses
2021-09-01T00:00:00ZOptimization of Battery Management System on Nano SatelliteEdet, David Kokoettehttp://repository.aust.edu.ng/xmlui/handle/123456789/50852022-08-31T21:00:51Z2021-09-10T00:00:00ZOptimization of Battery Management System on Nano Satellite
Edet, David Kokoette
Battery Management Systems (BMS) are tasked so as to provide an optimum and efficient control over the battery in any satellite EPS. Along with efficiency, these systems also require intelligent safety measures to avoid catastrophic failure when working in space environment. For a large scale of battery pack, the accumulation of the heat generated during the charging and discharging processes might lead to the increase in temperature in the battery pack and thus causing the faster acceleration of electrochemical reaction, this can reduce the battery lifespan and seriously affect the battery charging capability and safety. However, overcharging and the short circuit issue in high thermal condition of battery pack may cause battery damage. For this cause, this thesis aim is to optimizes the charging current so as to minimize the charging time for fast charging of battery before the satellite approaches eclipse, by utilizing a Social Group Optimization Algorithm to overcome the state of charge (SOC) problem whereby improving the battery lifespan. The approached used, account for the reduction of charge time with an efficiency 95.51% compared with other technique used. This entitles that this proposed method performed best over the previous technique and are easy to implement considering all the charging process, which allows maximum protection of the battery from overvoltage, overcharging and overheating conditions. The result shows an almost 9min decrease in the charging time without affecting the capacity and the life cycle which is most significant for the battery life.
2021 Aerospace Engineering Masters Theses
2021-09-10T00:00:00ZEstimation of Shortwave Broadband Irradiance at the Bottom of the Atmosphere Over Ilorin in Central Nigeria Using Radiative Transfer ModelDauda, Kashim Auduhttp://repository.aust.edu.ng/xmlui/handle/123456789/50842022-08-31T21:00:47Z2021-09-01T00:00:00ZEstimation of Shortwave Broadband Irradiance at the Bottom of the Atmosphere Over Ilorin in Central Nigeria Using Radiative Transfer Model
Dauda, Kashim Audu
Shortwave Broadband Irradiance (SBI) makes up about 96% of the Total Solar Irradiance (TSI) received on earth, and it is known to be the major driver of climate change. The SBI also contains ultraviolet radiation, which is harmful to inhabitants of Earth. The Direct
Normal Irradiance (DNI) and Global Horizontal Irradiance (GHI) received at the surface in Ilorin (8.484°N, 4.675°E), Central Nigeria, have been computed using a radiative transfer model: the Simple Model of the Atmospheric Radiative Transfer of Sunshine (SMARTS). The spectral range of the study was from 280 to 4000 nm under cloudless conditions, using aerosol retrieval data from Ilorin AERONET station for the year 2020. The results were compared to the satellite based dataset of the Copernicus Atmosphere Monitoring Service
(CAMS) McClear Clear-Sky Irradiation service, and showed good correlation for both sources of irradiance for the period of study. The results show that the RMSEs were comparatively low for most of the year, except during the dry season when the RMSE for the Direct Normal Irradiance (DNI) reached 171.77 W/m2. This implies that the Copernicus Atmosphere Monitoring Service (CAMS) McClear Clear-Sky Irradiation service data is fairly accurate for estimating the irradiance values during the wet and dry seasons in Nigeria, but not for Direct Normal Irradiance (DNI) during the dry season
2021 Aerospace Engineering Masters Theses
2021-09-01T00:00:00Z