Velocidade e energia cinética da chuva de um emissor usado em pivô central

• Ano de defesa: 2010
• Autor(a) principal: Ferreira, Denise de Jesus Lemos
• Orientador(a): Lima, Luiz Antônio
• Banca de defesa: Colombo, Alberto, Rezende, Fátima Conceição
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DEG - Programa de Pós-graduação
• País: BRASIL
• Palavras-chave em Português: Energia cinética; Velocidade de impacto; Uniformidade de distribuição; Kinetic energy; Impact velocity; Distribution uniformity
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/3210

Soil erosion causes great impact on potential yield of cultivated areas. Therefore, the study of velocity and kinetic energy of water droplets hitting the surface of irrigated soil is very important for diagnostics and procedures to minimize negative effects on irrigated areas. Accordingly, the objective is to measure the impact velocity and kinetic energy of artificial rainfall of the Super Spray (Senninger Irrigation). The evaluation of the kinetic energy and the impact velocity of the drops were performed using the dynamic rain gage system (SDP) at the Laboratory of Hydraulics and Irrigation at the Federal University of Lavras (UFLA). Water distribution uniformity where the SDP system was positioned was measured. The experimental design was completely randomized (CRD), referring to the six nozzles (treatments) with three replications. It was found that values of impact velocity and kinetic energy did not differ significantly for the nozzles tested. It could be observed that the three smaller nozzle diameters (5.75, 6.94 and 7.54 mm) favored higher intensities at the outer end near the sprayer, while the three larger nozzles (8.33 , 9.33 and 10.12 mm) tended to increase rain intensity on the outside of the catch can mesh. The uniformity coefficient values, CUC and CUD, were satisfactory for use of the SDP methodology for the top five nozzle diameters (6.94, 7.54, 8.33, 9.33 and 10.12 mm), while for 5.75 mm nozzle, the value of the CUD (83.74%) was comparatively low, not ensuring uniformity requested by the SDP method. It was also found that Super Spray used on center pivot presented lower kinetic energy when compared to natural rainfall with the same intensity, according to estimates of empirical models available in the literature. The kinetic energy is not related to nozzle size tested. The dynamic rain gage system measures the speed and kinetic energy of uniform rain (no spatial variability), although it might present discrepant values of rainfall kinetic energy when the coefficient of uniformity of distribution (CUD) is lower than 84%. The flow rates measured by volumetric method were closer to values listed by manufacturer.