scholarly journals Investigations of Rod Positions for Treat M8CAL Analyses

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Zachary Weems ◽  
Sedat Goluoglu ◽  
Mark D. DeHart
Keyword(s):  
Significant Role ◽  
Transient Analysis ◽  
Boron Concentration ◽  
Three Dimensional ◽  
Test Facility ◽  
Initial Transient ◽  
Reactor Test ◽  
Experimental Values ◽  
Reactor Models ◽  
Reactivity Insertion

The transient reactor test facility (TREAT), a graphite moderated experimental reactor, is scheduled to restart in late 2017. There is now renewed interest in development of capabilities to model and simulate the TREAT transients using three-dimensional coupled physics. To validate existing transient analysis tools as well as those under development, several temperature-limited transients have been modeled and analyzed. These transients are from the M8 calibration (M8CAL) experiment series, a set of experiments performed to calibrate the reactor detectors for the planned M8 series of fuel tests. Detailed reactor models were prepared that were then used to calculate the pretransient and post-transient keff values as well as corresponding reactivity insertions. Alterations to modeled values of shutdown and initial transient rod insertion depths were made to better match the reported experimental values of reactivity insertions assuming just critical pretransient states. It was found that two of the altered media inputs, fuel and Zircaloy-3 cladding, had significant effects on the keff. In addition, increasing shutdown rod insertion by 3–5 cm and decreasing initial transient rod insertion by 1–2 cm gave perfect pretransient keff and total reactivity insertion values. However, the revised positions are as much as a factor of 3–20 different from reported uncertainty of 0.762 cm. This suggests that boron concentration uncertainties may play a significant role in accurately modeling the TREAT transients and should be investigated thoroughly.

Experimental Investigation of Coolant Mixing in the RPV of PWR in the Late Phase of a SBLOCA Event

2006 ◽  
Author(s):  
So¨ren Kliem ◽  
Horst-Michael Prasser ◽  
Tobias Su¨hnel ◽  
Frank-Peter Weiss ◽  
Asmus Hansen
Keyword(s):  
Boron Concentration ◽  
Natural Circulation ◽  
Outer Part ◽  
Wire Mesh ◽  
Test Facility ◽  
Primary Circuit ◽  
Pressurized Water ◽  
The Core ◽  
Borated Water ◽  
Reactivity Insertion

Partial depletion of the primary circuit of a pressurized water reactor during a postulated small break loss of coolant accident can lead to interruption of one-phase flow natural circulation. In this case, the decay heat is removed from the core in the reflux-condenser mode. In this operation mode, slugs of lower borated water can accumulate in the cold legs. After refilling of the primary circuit, the natural circulation in the two loops not receiving emergency core cooling injection (ECC) re-establishes and the lower borated slugs are shifted towards the reactor pressure vessel (RPV). Entering the core, the lower borated water causes a reactivity insertion. Mixing inside the RPV is an important phenomenon limiting the reactivity insertion and preventing a re-criticality. The mixing of these lower borated slugs with the ambient coolant in the RPV was investigated at the 1:5 scaled coolant mixing test facility ROCOM. Wire mesh sensors based on electrical conductivity measurement are used in ROCOM to measure in detail the spreading of a tracer solution in the facility. The mixing in the downcomer was observed with a sensor which spans a measuring grid of 64 azimuthal and 32 positions over the height. The resulting distribution of the boron concentration at the core inlet was measured with a sensor integrated into the lower core support plate providing one measurement position at the entry into each fuel assembly. The boundary conditions for the mixing experiment were taken from an experiment at the thermal-hydraulic test facility PKL operated by FANP Germany. The slugs, which have a lower density, accumulate in the upper part of the downcomer after shifting into the RPV. The ECC-water injected into the RPV falls almost straight down through the lower borated water and accelerates. On the outer sides of the ECC-streak, lower borated coolant admixes and flows together with the ECC-water downwards. This is the only mechanism of transporting the lower borated water into the lower plenum. All these effects could be visualized and quantified by the downcomer sensor. On the way to the core, the lower borated water is effectively mixing with the ambient, high borated water. Therefore, in the core inlet plane, lower borated water is detected only in the outer part. The minimum boron concentration, measured at one fuel element inlet position at one certain time point, was 71% of the initial 2500 ppm. There is no change of the initial boron concentration in the inner part of the core inlet plane during the whole transient at all.

The MIT Blowdown Turbine Facility

1984 ◽  
Author(s):  
A. H. Epstein ◽  
G. R. Guenette ◽  
R. J. G. Norton
Keyword(s):  
Heat Transfer ◽  
Fluid Mechanics ◽  
Short Duration ◽  
Three Dimensional ◽  
Inlet Pressure ◽  
Test Facility ◽  
Turbine Inlet ◽  
High Work

A short duration (0.4 sec) test facility, capable of testing 0.5-meter diameter, film-cooled, high work aircraft turbine stages at rigorously simulated engine conditions has been designed, constructed, and tested. The simulation capability of the facility extends up to 40 atm inlet pressure at 2500°K (4000°F) turbine inlet temperatures. The facility is intended primarily for the exploration of unsteady, three-dimensional fluid mechanics and heat transfer in modern turbine stages.

Three-dimensional particle simulation of back-sputtered carbon in electric propulsion test facility

2017 ◽  
Vol 132 ◽  
pp. 161-169 ◽  
Author(s):  
Hongru Zheng ◽  
Guobiao Cai ◽  
Lihui Liu ◽  
Shengfei Shang ◽  
Bijiao He
Keyword(s):  
Electric Propulsion ◽  
Three Dimensional ◽  
Particle Simulation ◽  
Test Facility

Simulation of Three-Dimensional Stress Distribution in Compression Dies

2008 ◽  
Vol 575-578 ◽  
pp. 449-454
Author(s):  
Chu Yun Huang ◽  
Sai Yu Wang ◽  
Tao Yang ◽  
Xu Dong Yan
Keyword(s):  
Stress Distribution ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Distribution Model ◽  
Extrusion Dies ◽  
Maximum Value ◽  
Multiple Unit ◽  
Stress Freezing Method ◽  
Experimental Values ◽  
Aided Design

The stress fields of rectangular and T shape compression dies were simulated by three dimensional photo-elasticity of stress freezing method. The rules of stress distribution of σx, σy, σz on the surface of rectangular and T-shaped dies were discovered, and the rules were also found inside the dies. The results indicate that the stress distribution of rectangular die is similar to that of T shape die. Obvious stress concentration in corner of die hole was observed. σz rises from die hole to periphery until it achieves maximum value then it diminishes gradually, and σz between die hole and fix diameter zone is higher than it is in other position. At the same time, the equations of stress field of extrusion dies were obtained by curved surface fitting experimental values in every observed point with multiple-unit regression analysis method and orthogonal transforms. These works can provide stress distribution model for die computer aided design and make.

Three-Dimensional Seismic Response Analysis of Buried Continuous or Jointed Pipelines

1987 ◽  
Vol 109 (1) ◽  
pp. 80-87 ◽  
Author(s):  
S. Takada ◽  
K. Tanabe
Keyword(s):  
Seismic Behavior ◽  
Ground Motions ◽  
Three Dimensional ◽  
Response Analysis ◽  
Ground Deformations ◽  
Pipe Systems ◽  
Experimental Values ◽  
Earthquake Response Analysis ◽  
Nonlinear Behaviors ◽  
Torsional Properties

This paper presents a three-dimensional quasi-static analysis of continuous or jointed pipelines. Transfer Matrix Method was applied to the analysis providing for nonlinear behaviors of joints and soil frictions. An improved computer program ERAUL-II (Earthquake Response Analysis of Underground Lifelines-II) was developed for numerical computations. First, numerical response analyses were carried out for three-dimensional pipe systems with steel or cast iron pipe materials subject to large ground deformations or seismic ground motions. Analytical results show that torsional properties of pipes are also important factors for seismic behavior, which cannot be known by two-dimensional analyses. Second, experimental test data of three-dimensional steel pipe systems were simulated by using the ERAUL-II program. Simulated results agree well with the experimental values.

THREE‐DIMENSIONAL TRANSIENT ANALYSIS OF A SINGLE SUBMERGED CYLINDRICAL SHELL

1991 ◽  
Vol 8 (3) ◽  
pp. 195-213 ◽  
Author(s):  
R.K. SINGH ◽  
T. KANT ◽  
A. KAKODKAR
Keyword(s):  
Cylindrical Shell ◽  
Transient Analysis ◽  
Three Dimensional

Blade-Row Interactions in an LP Turbine at Design and Strong Off-Design Operation

2014 ◽  
Author(s):  
Martin Lipfert ◽  
Jan Habermann ◽  
Martin G. Rose ◽  
Stephan Staudacher ◽  
Yavuz Guendogdu
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Three Dimensional ◽  
Suction Side ◽  
Test Facility ◽  
Time Resolved ◽  
Joint Project ◽  
Multi Stage ◽  
Blade Row ◽  
Wake Interactions

In a joint project between the Institute of Aircraft Propulsion Systems (ILA) and MTU Aero Engines a two-stage low pressure turbine is tested at design and strong off-design conditions. The experimental data taken in the altitude test-facility aims to study the effect of positive and negative incidence of the second stator vane. A detailed insight and understanding of the blade row interactions at these regimes is sought. Steady and time-resolved pressure measurements on the airfoil as well as inlet and outlet hot-film traverses at identical Reynolds number are performed for the midspan streamline. The results are compared with unsteady multi-stage CFD predictions. Simulations agree well with the experimental data and allow detailed insights in the time-resolved flow-field. Airfoil pressure field responses are found to increase with positve incidence whereas at negative incidence the magnitude remains unchanged. Different pressure to suction side phasing is observed for the studied regimes. The assessment of unsteady blade forces reveals that changes in unsteady lift are minor compared to changes in axial force components. These increase with increasing positive incidence. The wake-interactions are predominating the blade responses in all regimes. For the positive incidence conditions vane 1 passage vortex fluid is involved in the midspan passage interaction leading to a more distorted three-dimensional flow field.

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