Models of adaptation of the milking machines systems

Two systems of milking machines were considered - biotechnical and vacuum. Methodology for estimation of efficiency of the "machine-animal" biotechnical system was worked out. The dependences of the efficiency parameters of the technical system operation were analyzed. The KMMO operator load factor of the milking machine was proposed. The factor characterizes the technological process of the machine milking. The analytical dependences were worked out for the simulation of the productivity of milking machines and oscillation of the vacuum-gage pressure. As to the simulation results, when the vacuum pipeline diameter was increased the oscillation of the vacuum-gage pressure decreased. The results of analysis and theoretical researches on technological process of the cow machine milking gave a possibility to define the requirements to the improvement of technological process and technical equipment, which will provide the increase of efficiency of the milking systems. Usage of the developed cyber-physical system of the machine milking of cows will increase the productivity of the milking machine in 1.26…1.85 times. At the vacuum gage pressure oscillation of ΔPvp = 2500 Pa the suction ability of milking machine will be E=4.093 m/s accordingly. The defined index of efficiency of the adapted systems functioning of the milking machine is KBTS2 = 55.3.

Micro-Tribology of Flow-Induced Load on a Surface Asperity Using Lattice Boltzmann Method

In this paper flow around a single roughness, known as asperity, is examined using Lattice Boltzman Method. Elliptical asperity cross section is used for this study. Asperity of various aspect ratios, defined as width-over-thickness ratios are studied using two flow conditions. The flow conditions correspond to parallel (Poisuelle) flow and pressure-driven flow. Results show that negative gage pressure occurs under both flow conditions, in the first due to the flow vortices and in the latter due to emergence and growth of boundary layer. Asperity aspect ratio is shown to give rise to the pressure drop potentially leading to cavitation condition.

Thermal Performance Representation and Testing of Air Solar Collectors

The thermal performance of a plate-type air collector was evaluated experimentally. Tests were performed at the two ASHRAE Standard 93-1986 recommended flowrates and at a variety of inlet gage pressures to cover the three possible cases of collector leakage (inward, outward, inward-outward). These tests show that the thermal performance of air collectors depends on flowrate and inlet gage pressure (or the associated leakage rate). If the collector is used at an inlet gage pressure near atmospheric pressure as is often the case in the no-storage type of systems, then it is recommended to test the collector at an inlet gage pressure of zero. For collectors operating at various inlet gage pressures it is suggested to test them at three inlet gage pressures. As for the test flowrate, the present work confirmed the results of other studies and emphasizes the need to test the collectors at the design flowrate. Three methods of thermal performance representation were used and compared: One method bases the efficiency on the inlet flowrate, another on the outlet flowrate, and the third involves an overall enthalpy balance. When plotted in the classic way, that is, η vs. (Ti − Ta)/G the three methods exhibit significant differences, especially for the inward leakage case. An uncertainty analysis on the data obtained for this study indicates that for the inward leakage case, unacceptable uncertainties occur at high values of (Ti − Ta)/G.