A unified dynamic similitude model for solid continuum

Copyright © 2022 The Authors. Dynamic similitude has proven to be a valuable tool, which is widely adopted in fluid mechanics. However, even with the ever-growing interest in dynamic similitude in solid mechanics, there is still no unified scaling law applicable to any given solid structure or system, and this has prevented the broad adoption of similitude in the field. Here we develop a unified similitude model for solid mechanics using the momentum and the energy conservation. The model allows for the use of different materials in both elastic and plastic regimes. Never reported dimensionless numbers are derived for the first time in this article, and this set of numbers is sufficient for strictly accurate dynamic similitude of any solid structure. Very different case studies are considered, and the perfect agreement seen in compared results confirms the accuracy of the developed scaling model. The exactness of the dimensionless numbers is also confirmed through analytical solutions. The model allows for the scaling of strain rate and, for the first time, the scaling of the strain state between the full-scale structure and its scaled replica

Numerical Investigation into the Effects of Turbulence Modelling on the Aeroelastic Analysis of Flexible Wings

Copyright © 2022 The Authors. As wings are becoming more flexible, existing aeroelastic analysis methods may struggle to accurately resolve the complex flow around oscillating wings. A numerical case study is performed to compare the aeroelastic predictions obtained for a wing with two degrees of freedom when turbulence models of varying fidelity are used. Results are presented and compared in the time and frequency domain for simulations using Reynolds Averaged Navier Stokes and Detached Eddy turbulence models. These results show significant differences be- tween the results obtained, particularly in the time domain. The numerical methodology, setup and results for this case study are presented in this paper

A Unified Dynamic Similitude of Solid Continuum and its Application in Aeroelastic Structures

Copyright © 2022 The Authors. The use of dynamic similitude has been widely proven in fluid mechanics. With the drive for efficient aircraft wing through high aspect ratio wings comes the growing need for much more accurate aeroelastic analyses of aircraft wings and more accurate scaled experimental tests. Even with this need for dynamic similitude in solid mechanics, there is still no unified exact scaling law applicable to any given solid structure or system. Here we present a recently proposed unified similitude model for solid mechanics using the momentum and the energy conservation. The model allows for the use of different materials in both elastic and plastic regimes. Never reported dimensionless numbers are derived for the first time in this article, and this set of numbers is sufficient for strictly accurate dynamic similitude of any solid structure. The application of the unified model is demonstrated for the first time in an aeroelastic structure and in aerospace structures through case studies. The very good agreement seen in compared results confirms the accuracy of the developed scaling model and the exactness of the dimensionless numbers

Effect of associated vaccines on the interference between Newcastle disease virus and infectious bronchitis virus in broilers

The phenomenon of viral interference between live vaccines against Newcastle Disease and infectious bronchitis has been reported since the 50's and many researchers have reported its prejudicial effects on avian immunization. Therefore, this study evaluated the effect of associated vaccines on the interference between Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) in broilers. There were 400 broiler chicks divided into five groups. The groups were submitted to mono or polyvalent vaccinations against IBV and NDV, except for the non-vaccinated control group (CG). Sera were collected at 35 and 45 days of age and submitted to serologic tests to assess antibody levels. It was observed the occurrence of interference in the immune response against NDV by the use of associated vaccines to NDV and IBV; however, the group that was immunized with commercial combined vaccines (IBV+NDV) presented antibody titers to NDV similar to the group that was given only vaccine against NDV. We concluded based on these preliminary studies that the interference of IBV on the immune response against NDV depends also whether the association between the two vaccines is done just before vaccination or in the manufacturing laboratory

Bacteriological investigation of microorganisms (Salmonella sp. and other Enterobacteriaceae) in common quails (Coturnix coturnix) submitted to different forced-molting procedures

The aim of this study was to investigate the presence of Salmonella in common quails submitted to forced molting. A total of 240 quails were divided at 40 weeks of age into four groups: CG (control, quails not submitted to molting); FM (fasting method); WM (fed wheat midds ad libitum); and ZM (zinc oxide method). From each group, 10 cloacal swabs, 10 fecal samples, and 20 egg samples were collected before molting (two weeks) and after molting (two weeks). The microbiological procedures for Salmonella spp. identification were performed in four steps. The agglutination test, using somatic and flagellar antigens, was used to confirm Salmonella-suspected colonies. According to the methodology applied, none of the samples was positive for Salmonella spp. The results showed that 20.0% of the egg samples from birds submitted to forced molting were contaminated with enterobacteria. It was concluded that, under the conditions of the present experiment, the stress caused by forced molting did not induce infection by Salmonella spp. or increased Enterobacteriaceae contamination levels in the eggs

Interference of infectious bursal disease virus on antibody production against Newcastle disease and infectious bronchitis virus

This work has the objective of verifying the interference of infectious bursal disease virus in the antibody production against Newcastle disease virus and infectious bronchitis virus. The experiment was carried out with 640 day-old-chicks from a 42 weeks old hen flock. The birds were separated into eight experimental groups (n=80/group) and were submitted to different combinations of vaccinations, with live vaccines, to Newcastle disease, avian infectious bronchitis, and infectious bursal disease with diverse combinations of days of vaccination. We verified that the utilization of polyvalent vaccinal programs have a different efficacy comparing to monovalent vaccinations when Newcastle disease, infectious bronchitis, and infectious bursal disease vaccinations are applied. This way, the use of vaccinations to infectious bursal disease in polyvalent vaccinal programs is desirable due to improvement of NDV response with the presence of IBV by the probable reduction of interference of IBV under NDV