DSpace Collection:
https://ds.univ-oran2.dz:8443/jspui/handle/123456789/1869
2024-03-28T17:31:01ZRetrieval–travel-time model for free-fall-flow-rack automated storage and retrieval system
https://ds.univ-oran2.dz:8443/jspui/handle/123456789/2086
Titre: Retrieval–travel-time model for free-fall-flow-rack automated storage and retrieval system
Auteur(s): Metahri, Dhiyaeddine; Hachemi, Khalid
Résumé: Automated storage and retrieval systems (AS/RSs) are material handling systems that are frequently used in manufacturing
and distribution centers. The modelling of the retrieval–travel time of an AS/RS (expected product delivery time) is
practically important, because it allows us to evaluate and improve the system throughput. The free-fall-flow-rack AS/RS
has emerged as a new technology for drug distribution. This system is a new variation of flow-rack AS/RS that uses an
operator or a single machine for storage operations, and uses a combination between the free-fall movement and a transport
conveyor for retrieval operations. The main contribution of this paper is to develop an analytical model of the expected
retrieval–travel time for the free-fall flow-rack under a dedicated storage assignment policy. The proposed model, which is
based on a continuous approach, is compared for accuracy, via simulation, with discrete model. The obtained results show
that the maximum deviation between the continuous model and the simulation is less than 5%, which shows the accuracy
of our model to estimate the retrieval time. The analytical model is useful to optimise the dimensions of the rack, assess the
system throughput, and evaluate different storage policies.2018-03-21T00:00:00ZReliability Analysis by Mapping Probabilistic Importance Factors into Bayesian Belief Networks for Making Decision in Water Deluge System
https://ds.univ-oran2.dz:8443/jspui/handle/123456789/2081
Titre: Reliability Analysis by Mapping Probabilistic Importance Factors into Bayesian Belief Networks for Making Decision in Water Deluge System
Auteur(s): Guetarni, Islam H.M; Aissani, Nassima; Châtelet, Eric; Lounis, Zoubida2018-01-01T00:00:00ZEffects of proof tests on the safety performance of safety-instrumented systems
https://ds.univ-oran2.dz:8443/jspui/handle/123456789/2078
Titre: Effects of proof tests on the safety performance of safety-instrumented systems
Auteur(s): Asklou, Noureddine; Rachid, Noureddine
Résumé: The imperfection in the values of the average probability of failure
on demand (PFDavg) creates uncertainty about the effectiveness of
safety-instrumented system (SIS). To overcome this problem, many parameters
such as dangerous failures, common cause failures, diagnostic coverage rate
and proof tests are taken into consideration. In order to emphasise the
importance of the proof tests and show their effects on the safety performance
of the SIS, a new analytical formula is developed in this study. The impact of
these tests on the SIS’s allocation of the safe integrity level (SIL) is shown
through the results obtained in the present research.2018-01-01T00:00:00ZNUMERICAL SIMULATION OF TURBULENT THERMAL MIXING IN A RECTANGULAR T-JUNCTION
https://ds.univ-oran2.dz:8443/jspui/handle/123456789/1901
Titre: NUMERICAL SIMULATION OF TURBULENT THERMAL MIXING IN A RECTANGULAR T-JUNCTION
Auteur(s): BESSAID, Bouchra Sarah; Dellil, Ahmed Zineddine; Nemdili, Fadéla; Azzi, Abbès
Résumé: This work reports three-dimensional simulation results of thermal mixing in a rectangular T-junction configuration at high Reynolds number. The validation data are provided by an experimental study done at the Department of Mechanical Engineering of Mie University, Japan. The T-junction was selected as a benchmark for thermal mixing in the ERCOFTAC Workshop held in EDF Chatou, France, 2011. Reynolds-averaged Navier-Stokes (RANS), unsteady Reynolds-averaged Navier-Stokes (URANS), and scale-adaptive simulation (SAS) were performed with CFD code using the finite-volume method. Velocity and thermal field as well as the turbulent stresses are reported and compared to experimental data in several longitudinal stations. It was found from the comparison that URANS methodology cannot reproduce the striping phenomenon, and secondly, that the SAS model fit better than the shear stress transport model with experimental data. Additional contours of averaged longitudinal velocity end thermal field as well as the flow structures developing in the channels are presented and discussed.2017-01-01T00:00:00Z