Inka Hydraulic Engineering at the Tipon Royal Compound (Peru)

The Inka site of Tipon had many unique hydraulic engineering features that have modern hydraulic theory counterparts. For example, the Tipon channel system providing water to the Principal Fountain had a channel contraction inducing critical flow as determined by CFD analysis- this feature designed to induce flow stability and preserve the aesthetic display of the downstream Waterfall. The Main Aqueduct channel sourced by the Pukara River had a given flow rate to limit channel overbank spillage induced by a hydraulic jump at the steep-mild slope transition channel location as determined by use of modern CFD methods- this flow rate corresponds to the duplication of the actual flow rate used in the modern restoration using flow blockage plates placed in the channel to limit over-bank spillage. Additional hydraulic features governing the water supply to agricultural terraces for specialty crops constitute further sophisticated water management control systems discussed in detail in the text.

Rationing of fuel consumption based on identification of rolling stock modes

The article presents the results of a study of innovative technology on improving the rationing of diesel fuel consumption on rolling stock in the railway industry. As an object of research, fuel consumption was studied on a Automotrisa diesel editing - ADE-1, which is used in the electrification and power supply facilities of the Transenergo Directorate. Motorized carriage loading transport (MLT – 6), which is used in the economy of the track. On the basis of a number of regulatory documents of the Russian Railways company, the Samara State University of Railway Transport was entrusted with the analysis of the efficiency of fuel consumption of SSPS on these types of rolling stock at one of the railway landfills. The special self-propelled rolling stock of the Russian Railways company was studied as an object of research. The method of forming fuel consumption standards by identifying the actual values of fuel consumption and indicators of rolling stock operating modes is considered. The statistical methods used in the research allow us to set the rate of consumption in the range of 8% of the actual flow rate. Based on the use of the obtained fuel consumption rate, a method for identifying and evaluating the level of unauthorized fuel overspendings (draining) is provided.

Distribution of kinetic energy losses between nozzles and turbine impeller on partial gas supply modes

В статье приведены результаты экспериментальных исследований связанных с распределением потерь кинетической энергии между сопловым аппаратом и рабочим колесом у осевых малорасходных турбинных ступеней. У всех ступеней конструктивные углы выхода сопел были менее 9°, что повлекло за собой необходимость выполнения рабочих колес с относительным шагом установки рабочих лопаток значительно большим, рекомендованного в технической литературе. Исследования проведены для ступеней со средним диаметром 250 мм. Диапазон изменения факторов составил: отношение давлений перед соплами к давлению за ступенью от 2.0 до 5.0; частоты вращения вала с рабочим колесом от 0 до 14000 . Эффективность использования кинетической энергии приведена в виде коэффициентов скорости соплового аппарата и рабочего колеса. Коэффициенты представляют собой отношение реальной скорости потока на выходе из соплового аппарата (рабочего колеса) к теоретически возможной скорости газа в выходном сечении рассматриваемого элемента ступени. Выявлено, что коэффициенты скорости сопловых аппаратов и рабочих колес изменяются не только при смене режимных параметров, таких как частота вращения ротора и отношения давлений на ступень, но и при изменении степени парциальности ступени. The article presents the results of experimental studies related to the distribution of kinetic energy losses between the nozzle apparatus and the impeller at axial low-flow turbine stages. At all stages, the design angles of the nozzle exit were less than 9 °, which entailed the necessity of making impellers with a relative pitch of the rotor blades that was much larger, as recommended in the technical literature. The studies were carried out for steps with an average diameter of 250 mm. The range of variation of the factors was the ratio of the pressures in front of the nozzles to the pressure behind the stage from 2.0 to 5.0; rotation speed of the shaft with the impeller from 0 to 14000 rpm. The efficiency of using the kinetic energy is given in the form of the coefficients of the speed of the nozzle apparatus and the impeller. The coefficients represent the ratio of the actual flow rate at the outlet of the nozzle apparatus (impeller) to the theoretically possible gas velocity in the outlet section of the stage element under consideration. It was found that the speed coefficients of the nozzle apparatus and impellers change not only when changing operating parameters, such as the rotor speed and the pressure ratio per stage, but also when changing the degree of stage partiality.

Indirect estimation of the production rate of wells with low flow rate

The problem of measuring the flow rate of wells with low production rates is relevant for many oil fields. Conventional flow meters are not suitable for such cases, and installing an additional flow meter for each well is impractical. At the same time, wells with sucker-rod pumping units (the majority of wells) are outfitted with dynamographs for continuous diagnostics of the pumping equipment state. Dynamograms allow determining the theoretical flow rate of the well easily, however, a mathematical model is required to estimate the actual flow rate. For the correction of flow rate obtained from dynamograms, the authors of this study propose using models based on regression equations that link the calculated valueswith the measurements made by a reference instrument. The results of the experiments have confirmed the eligibility of this approach.

FEATURES OF THE STAND AND METHODS FOR EXPERIMENTAL STUDIES OF PUMP-DOSING PUMPS OF HYDRAULIC STEERING SYSTEMS OF SELF-PROPELLED VEHICLES UNDER THE ASSOCIATED LOAD

The article discusses a special stand for experimental research of dosing pumps of hydrostatic steering systems of self-propelled machines, which makes it possible to analyze the quality of the dosing pump under conditions that correspond to different control actions and loads that arise during the operation of the steering system. An electro-hydraulic scheme of the stand has been developed to determine the characteristics of a dosing pump under the action of a associated load. The characteristics of control and measuring devices for determining parameters that are controlled both in statics and in dynamics are presented. To record changes in signals over time, a recording system has been developed that realizes the recording of signals on a computer and their processing using the «PowerGraph» program. A feature of this stand is that the load for the dosing pump is formed in the form of a pressure drop in its outlet channels. This makes it possible to evaluate the performance of these products regardless of their working volume and facilitates the experimental study of the behavior of the system when reproducing certain modes of its operation over a period of time that is not limited to the stroke of the executive hydraulic cylinder of the steering system. The stand implements an original technique for reproducing the associated load in the outgoing channels of the dosing pump, for which an additional pump driven by a hydraulic motor is installed in the outgoing channels of the metering pump. Regulation of the speed of rotation of the drive motor makes it possible to set the required value of the associated load. The method for determining the quality indicator of the dosing pump operation under the action of a associated load is briefly described In this case, the indicator of relative flow rates in the outgoing channels of the metering pump is determined, which shows how many times the actual flow rate of the working fluid increases in comparison with the nominal one, which is determined for the dosing pump with a certain working volume by the speed of rotation of the input shaft.

A New Method for Performance Measurement of PPV Fans for Fire Fighting Under Realistic Conditions

PPV Fans (Positive Pressure Ventilation Fans) are used in firefighting to remove smoke from a burning building, so that fire fighters can have a clear view inside the house and injured people do not have to breathe toxic smoke. This can be done by placing a PPV fan in a distance of about two meters in front of a door of the burning building. On another, carefully chosen position in the building, e. g. a window, a door or at the roof an opening has to be created, where the smoke can leave the building. The same volumetric flow rate of gas that is blown into the building by the PPV fan has to leave the building at a chosen opening. Because the gas entering the building is air and the gas leaving the building is a mixture of smoke and air, the smoke concentration in the building can be reduced. To test the performance of such PPV fans, a test building with a door in the first floor and a window in the 3rd floor has been built. To measure the volumetric flow rate of the smoke and air mixture through the window in the 3rd floor that is leaving the building, a flow meter nozzle was designed. The design process was done using the commercial Navier Stokes solver Star CCM+, where three nozzle designs, such as a nozzle with constant velocity increase, a quarter circle nozzle and a non-curved nozzle were investigated for different volumetric flow rates. Also, a rounding at the window, where the nozzle is placed, was investigated to prevent flow detachment and shock losses at the inlet of the nozzle. The volumetric flow rate through the nozzle can be calculated, by measuring the pressure at the nozzle wall (before the contraction) and applying Bernoulli’s law, the continuity equation and assuming atmospheric pressure at the free jet flow at the end of the nozzle. The so calculated volumetric flow rate was compared with the actual flow rate, given by the numerical CFD simulations. With these values, the nozzle specific coefficient of discharge for several volumetric flow rates has been calculated and a function fitting was done to get obtain analytical relation between pressure and volumetric flow rate. The detailed design process of the three nozzles, the numerical results of the CFD studies and the determination of the nozzle specific coefficients of discharge are shown and discussed in detail in this work.

Determination of qualitative indicators of the work of the wide sprinkling machine

The aim of the research is to select the diameters of the nozzles of the deflector nozzles and to determine the quality indicators of the operation of a new wide-grip sprinkler of circular action, developed at the Federal State Budgetary Scientific Institution «RosNIIPM». The selection of the diameters of the nozzles of the deflector nozzles was carried out from the conditions of passing three different flows through the DM water pipeline: 15, 30 and 60 l/s. The scheme of their arrangement – rain-forming devices have different flow rates and diameters of nozzles at the same distance between them along the DM water-conducting pipeline. The analysis of the results obtained showed small deviations in the actual flow rate of the deflector nozzles through the water pipeline (cf. deflector nozzles with calculated nozzle diameters. Investigations of irrigation uniformity were carried out, as a result of which the following results were obtained: effective irrigation coefficient – 0.67–0.78; the coefficient of insufficient irrigation is 0.10–0.12, the coefficient of excessive irrigation is 0.12–0.15. At the same time, a decrease in the uniformity of irrigation is associated with an increase in wind speed and thereby an increase in the drift of artificial rain drops, the worst condition for the use of a WDM is a wind speed of more than 5 m/s, and therefore it is recommended to use this DM in the morning and evening, characterized by a more reduced wind load.

A study on the hopper unloading duration of the harvesting machine at different technical parameters

When unloading grain harvester hoppers at standstill the time of emptying the hopper has a significant effect on the harvester productivity. The paper is about a conducted survey in 15 agricultural farms with 15 harvesters monitored including 14 models of 6 different brands during wheat harvesting. The time for emptying the grain hopper of the harvesters was defined by measuring the time. It was found that the actual time for emptying the hoppers of the studied harvesters was 134.85 s, and the actual flow rate of unloading of the screw in them being 69.63 L/s on average. A multivariate regression analysis was performed on the effect of the harvester grain hopper volume and the actual flow rate of the unloading screw on the time from switching on the unloading screw till its switching off in various grain harvesters. An adequate mathematical model of the effect of the hopper volume and the flow rate of the unloading screw of grain harvesters on the time for emptying the grain hopper under real production conditions has also been created. These results can also be used for minimizing costs in the technological process at harvesting.

INFLUENCE OF THE USE OF GRAVITY SETS IN A PRESSURE VOLUMETRIC INFUSION PUMP WITH AN IMPACT ON THE ACCURACY OF INFUSION SOLUTION FLOWS

The subject of the work was the experimental verification of the negative influence of gravity sets in a pressure volumetric infusion pump with an impact on the accuracy of infusion solution dosing. The quality criterion for gravity sets was the accuracy of the flow versus the reference set by the volumetric infusion pump. The solution consisted of 14-hour measurements with two types of gravity sets, Intrafix® Primeline sets were used as universal sets and Standardline IS‑103 gravity sets. The insulin pump flow rate was set at 300 ml/h and 50 ml/h, and the actual flow rate of the infusion solution was recorded every hour using a graduated cylinder. Used gravity sets were also processed by mechanical tests, unused sets were subjected to these tests and the obtained data were compared with each other. Experiments carried out showed that at the set flow rate of 300 ml/h, the flow error with the universal set was -3% and at a set flow rate of 50 ml/h the error was +2.3%. Flow accuracy using gravity sets was worse, a flow error of -7.2% was detected for a flow rate of 50 ml/h and a flow error of -7.7% was measured for 300 ml/h. The volumetric pump used declares a tolerated inaccuracy of ± 3% when used with standard infusion sets. Based on the data, it can be concluded that the replacement of set types has an influence on the dosage of infusion solutions.