Dimensionless Criteria Energy Dissipation of Dynamically Heating Surfaces
Issue:
Volume 2, Issue 2, April 2014
Pages:
25-30
Received:
21 March 2014
Accepted:
11 April 2014
Published:
20 April 2014
Abstract: In this paper, a discussion of results is presented for the dimensionless analysis of generating irreversibility of vessels in which mixing and heating of fluid are done simultaneously. In the first case, the impeller inside the mixing vessel is the heating body, and in the second case heating body is a fixed ring and the impeller inside the vessel provides only mixing of the fluid. The paper presents a comparative analysis of typical irreversible dimensionless parameters in both cases. A mathematical model is established to describe the thermal-hydraulic irreversibility of heating-mixing vessel which indirectly gives them the ability to minimize and maximize the efficiency of such a system. Also, the paper established typical relations between the dimensionless entropic values and power number, as for the water heater impeller and also for impeller, combined with a heating ring, which will enable comparison of the required power numbers
Abstract: In this paper, a discussion of results is presented for the dimensionless analysis of generating irreversibility of vessels in which mixing and heating of fluid are done simultaneously. In the first case, the impeller inside the mixing vessel is the heating body, and in the second case heating body is a fixed ring and the impeller inside the vessel...
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The Effect of Dynamic Bending Moments on the Ratchetting Behavior of Stainless Steel Pressurized Piping Elbows
Issue:
Volume 2, Issue 2, April 2014
Pages:
31-37
Received:
9 April 2014
Accepted:
15 April 2014
Published:
30 May 2014
Abstract: In this paper the ratchetting behavior of four pairs of stainless steel, long and short radius welding elbows is studied under conditions of steady internal pressure and in-plane, resonant dynamic moments that simulated seismic excitations. The finite element analysis with the nonlinear kinematic hardening model has been used to evaluate ratchetting behavior of the elbow under mentioned loading condition. Stress–strain data and material parameters have been obtained from several stabilized cycles of specimens that are subjected to symmetric strain cycles. The results show that the maximum ratcheting strain occurred mainly in the hoop direction at flanks. Ratcheting strain rate increases with increase of the bending loading level at the constant internal pressure. The results show that the FE method gives over estimated values comparing with the experimental data.
Abstract: In this paper the ratchetting behavior of four pairs of stainless steel, long and short radius welding elbows is studied under conditions of steady internal pressure and in-plane, resonant dynamic moments that simulated seismic excitations. The finite element analysis with the nonlinear kinematic hardening model has been used to evaluate ratchettin...
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