Numerical analysis of slid gate and neyrpic module intakes outflows in unsteady flow conditions

AbstractSince the intakes outflow variations have an impact on network performance, it is necessary to evaluate the behavior of different types of intake structures in unsteady flow condition. In the present study, a computer model has been developed in which unsteady Saint–Venant flow equations have been discretized using finite difference and Crank–Nicolson method. Water surface elevation at junctions is calculated implicitly using matrix properties and influence line technique. After model verification, main channel of Miandarband irrigation network and its five branches were simulated. The result showed that without any operation instruction, a 10% decrease in the upstream flow discharge will reduce the slid gate, Neyrpic single orifice Module and double orifice Module intakes outflows for about 17.6%, 3.04% and 2.56%, respectively. With operation instruction, the maximum loss of flow volume is 707m3 during the first 10h of operation for intake with slid gate

Emergency Operations of Sudden Water Pollution Accidents

Emergency operation technologies can help to make reasonable operation measures of hydraulic structures, which are important to control the scope of the effect arising from an event and reduce the harm caused thereby. The main canal of MRP is divided into three parts in case of sudden water pollution accidents: the accident pool, the upstream section of the accident pool, and the downstream section of the accident pool. For each part, the target and strategy for emergency operation technologies are discussed. With regard to an accident pool, multiple kinds of check gate closing methods, synchronous, asynchronous, identical speed, and different speed are put forward; for the upstream section, a new method of equal-volume operation is introduced; and for the downstream section, three emergency operation methods are proposed. The simulation result of case study shows that the methods raised in this chapter can be used to determine suitable emergency operation measures

Satellite on-board processing for earth resources data

Results of a survey of earth resources user applications and their data requirements, earth resources multispectral scanner sensor technology, and preprocessing algorithms for correcting the sensor outputs and for data bulk reduction are presented along with a candidate data format. Computational requirements required to implement the data analysis algorithms are included along with a review of computer architectures and organizations. Computer architectures capable of handling the algorithm computational requirements are suggested and the environmental effects of an on-board processor discussed. By relating performance parameters to the system requirements of each of the user requirements the feasibility of on-board processing is determined for each user. A tradeoff analysis is performed to determine the sensitivity of results to each of the system parameters. Significant results and conclusions are discussed, and recommendations are presented

NASA Tech Briefs Index, 1977, volume 2, numbers 1-4

Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977

Global sensitivity analysis for the boundary control of an open channel

The goal of this paper is to solve the global sensitivity analysis for a particular control problem. More precisely, the boundary control problem of an open-water channel is considered, where the boundary conditions are defined by the position of a down stream overflow gate and an upper stream underflow gate. The dynamics of the water depth and of the water velocity are described by the Shallow Water equations, taking into account the bottom and friction slopes. Since some physical parameters are unknown, a stabilizing boundary control is first computed for their nominal values, and then a sensitivity anal-ysis is performed to measure the impact of the uncertainty in the parameters on a given to-be-controlled output. The unknown physical parameters are de-scribed by some probability distribution functions. Numerical simulations are performed to measure the first-order and total sensitivity indices

Online Monitoring of the Osiris Reactor with the Nucifer Neutrino Detector

Originally designed as a new nuclear reactor monitoring device, the Nucifer detector has successfully detected its first neutrinos. We provide the second shortest baseline measurement of the reactor neutrino flux. The detection of electron antineutrinos emitted in the decay chains of the fission products, combined with reactor core simulations, provides an new tool to assess both the thermal power and the fissile content of the whole nuclear core and could be used by the Inter- national Agency for Atomic Energy (IAEA) to enhance the Safeguards of civil nuclear reactors. Deployed at only 7.2m away from the compact Osiris research reactor core (70MW) operating at the Saclay research centre of the French Alternative Energies and Atomic Energy Commission (CEA), the experiment also exhibits a well-suited configuration to search for a new short baseline oscillation. We report the first results of the Nucifer experiment, describing the performances of the 0.85m3 detector remotely operating at a shallow depth equivalent to 12m of water and under intense background radiation conditions. Based on 145 (106) days of data with reactor ON (OFF), leading to the detection of an estimated 40760 electron antineutrinos, the mean number of detected antineutrinos is 281 +- 7(stat) +- 18(syst) electron antineutrinos/day, in agreement with the prediction 277(23) electron antineutrinos/day. Due the the large background no conclusive results on the existence of light sterile neutrinos could be derived, however. As a first societal application we quantify how antineutrinos could be used for the Plutonium Management and Disposition Agreement.Comment: 22 pages, 16 figures - Version

Index to NASA Tech Briefs, January - June 1966

Index to NASA technological innovations for January-June 196

Adaptive and non-adaptive model predictive control of an irrigation channel

The performance achieved with both adaptive and non-adaptive Model Predictive Control (MPC) when applied to a pilot irrigation channel is evaluated. Several control structures are considered, corresponding to various degrees of centralization of sensor information, ranging from local upstream control of the di®erent channel pools to multivariable control using only prox- imal pools, and centralized multivariable control relying on a global channel model. In addition to the non-adaptive version, an adaptive MPC algorithm based on redundantly estimated multiple models is considered and tested with and without feedforward of adjacent pool levels, both for upstream and down- stream control. In order to establish a baseline, the results of upstream and local PID controllers are included for comparison. A systematic simulation study of the performances of these controllers, both for disturbance rejection and reference tracking is shown

Modeling and control of a multiple-pool channel

Questa tesi tratta l'analisi di un sottoinsieme della rete di canali del Cavallino, situata lungo la costa Veneziana che si estende da Punta Sabbioni al porto di Piave Vecchia. In particolare, questo lavoro si focalizza su modellizzazione, stima e controllo di una sequenza di canali, assumendo che le misure relative al livello della supercie dell'acqua e la posizione delle strutture di controllo siano disponibili. Una procedura basata su identificazione dei sistemi consente di analizzare e selezionare il modello grey box migliore tra quelli proposti tra ARX e OE, con l'obiettivo di stimare l'andamento del livello dell'acqua. L'obiettivo del controllo è regolare il livello dell'acqua della rete agendo sulle strutture idriche di controllo. Di conseguenza, viene proposto un tipo di controllo decentralizzato. In particolare, viene sfruttato il controllo multivariabile del livello dell'acqua a monte della struttura di controllo, tenendo in considerazione sia chiuse in superficie che sotto il livello dell'acqua. La soluzione proposta è implementata nell'ambiente Matlab e Simulink e si basa su controllori PI aumentati con un filtro passabasso, al fine di controllare il livello dell'acqua in caso di perturbazione di una sequenza di canali consecutivi.This project deals with the analysis of a subset of the water channel network of the Cavallino, that is the section of the Venetian coast that extends from Punta Sabbioni to Piave Vecchia harbor. In particular, this work focuses on modeling, estimation and control design of a multiple channel pools system, assuming that water level measurements and control structure position are available. A system-identication-based procedure is considered for the analysis and selection of an ARX and an OE grey box model, to estimate and control purposes. The control aim is to regulate the water level of the channel network by acting on the hydraulic structure position. Then, a decentralized control is implemented. In particular, a multivariable local upstream control strategy is exploited, involving a model that takes into account both weirs and gates hydraulic control structures. Lastly, a solution is implemented in Matlab and Simulink, based on PI controllers augmented with lowpass filters, in order to control the water level of multiple pools connected in series

Irregation Automation: A Systems Approach

This thesis defines areas in which the electrical engineer can assist in developing irrigation automation. Particular attention is given to a telemetry system for data transmission from soil moisture sensors. Present and future communication requirements in automated irrigation systems are also discussed