Applied Engineering Letters

115-119

Authors: A. Skulić, B. Stojanović, S. Radosavljević, S. Veličković

This paper deals with the analysis of impact of various factors on power loss and efficiency of worm gearing. Factors that significantly affect the power losses are, principally, types of materials of meshed gears and geometry of worm pair, type and viscosity of lubricating oils, input rotational speed, worm shape, loading, temperature, etc. Results of experimental tests of worm gearing efficiency are also presented in the paper. Tests were conducted according to planned experiment schedule on specialized device AT200, where single-stage worm gearboxes with transmission ratio i=18 has been used. During the test stage, oils of different viscosities (ISOVG 220, ISOVG 460 and ISOVG 680) have been used and their impact on efficiency was monitored. The values of efficiency level are determined at different input rotational speeds (circumferential velocity) and output torques (loads).

128-135

Authors: O. Kayode, O. A. Koya

Nigeria is currently experiencing energy deficit in terms of electrification.Development of renewable energy sources such as Sea wave energy may help augment this deficit. This paper set to investigate wave energy potential of the coast of Nigeria. Data required for estimating the wave energy potential of the coastal waters of Nigeria were obtained from WAVEWATCH III© wave generation model. The wave climate data were analyzed using basic statistical analysis such as average, mean, and range. Due to the scarcity of reliable measured wave climate data, an effort was made to investigate the relationship the mean monthly wave power may have with mean monthly rainfall. Establishing a good level of correlation will provide an alternative mean of forecasting wave power for the coastal region. The results show that the mean annual wave power magnitude generally decreases from the west coast (at 10.74 kW/m) to the east coast (at 5.64 kW/m) for the reference points considered. The most energetic months occurs during the rainy season while the least energetic months occur during the dry season. There is a strong positive correlation between mean monthly wave power and mean monthly rainfall at 5% significant level.