Sensitivities When Modeling Electrically-Assisted Forming

2012 ◽  
Author(s):  
Cristina J. Bunget ◽  
Wesley A. Salandro ◽  
Laine Mears
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Electrical Power ◽  
Transfer Model ◽  
Modeling And Analysis ◽  
Factors Affecting ◽  
Electrically Assisted ◽  
Stainless Steel 304 ◽  
Analysis Strategy ◽  
Electrically Assisted Manufacturing

Recent research by the authors has resulted in the conception of several methods of accounting for direct electrical effects during an Electrically-Assisted Manufacturing (EAM) process, where electricity is applied to a conductive workpiece to enhance its formability characteristics. The modeling and analysis strategy accounts for both mechanical effects and heat transfer effects due to the applied electrical power. This work presents a sensitivity analysis and explanation of several key material and process inputs during an Electrically-Assisted Forming (EAF) test on Stainless Steel 304 and Titanium Grades 2 and 5 specimens. First, the effect that the specific heat (Cp) value has on the model will be discussed and compared with another lightweight material. Second, the significance of all three heat transfer modes (conduction, convection, and radiation) will be noted, and any possible simplifications to the existing heat transfer model will be highlighted. Third, the general electroplastic effect coefficient (EEC) profile shape for the Stainless Steel 304 material will be compared to that of Titanium alloys. Fourth, a frequency analysis will be done on the data taken during the experiments, by way of a Fast Fourier Transform (FFT), and the variation of frequency response with the electric input is studied. Overall, this work provides insight into several factors affecting a material’s EEC profile, and also compares resulting EEC profiles of various materials.

Several Factors Affecting the Electroplastic Effect During an Electrically-Assisted Forming Process

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Wesley A. Salandro ◽  
Cristina J. Bunget ◽  
Laine Mears
Keyword(s):  
Electric Current ◽  
Cold Work ◽  
Electrical Power ◽  
Forming Process ◽  
Electroplastic Effect ◽  
Factors Affecting ◽  
Forming Load ◽  
Electrically Assisted ◽  
Grade 5 ◽  
Electrically Assisted Manufacturing

Recent development of electrically-assisted manufacturing (EAM) processes proved the advantages of using the electric current, mainly related with the decrease in the mechanical forming load and improvement in the formability. From EAM experiments, it has been determined that a portion of the applied electrical power contributes toward these forming benefits and the rest is dissipated into heat, defined as the electroplastic effect. The objective of this work is to experimentally investigate several factors that affect the electroplastic effect and the efficiency of the applied electricity. Specifically, the effects of various levels of cold work and contact force are explored on both Grade 2 and Grade 5 Titanium alloys. Thermal and mechanical data prove that these factors notably affect the efficiency of the applied electricity during an electrically-assisted forming (EAF) process.

scholarly journals Modeling of a Solar Receiver for Superheating Sulfuric Acid

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Justin L. Lapp ◽  
Alejandro Guerra-Niehoff ◽  
Hans-Peter Streber ◽  
Dennis Thomey ◽  
Martin Roeb ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Sulfuric Acid ◽  
Thermodynamic Analysis ◽  
Transfer Model ◽  
Heat Transfer Medium ◽  
Modeling And Analysis ◽  
Concentrated Solar Energy ◽  
And Performance ◽  
Solar Receiver ◽  
Individual Design

A volumetric solar receiver for superheating evaporated sulfuric acid is developed as part of a 100 kW pilot plant for the hybrid sulfur (HyS) cycle. The receiver, which uses silicon carbide foam as a heat transfer medium, heats evaporated sulfuric acid using concentrated solar energy to temperatures of 1000 °C or greater, which are required for the downstream catalytic reaction to split sulfur trioxide into oxygen and sulfur dioxide. Multiple parallel approaches for modeling and analysis of the receiver are used to design the prototype. Focused numerical modeling and thermodynamic analysis are applied to answer individual design and performance questions. Numerical simulations focused on fluid flow are used to determine the best arrangement of inlets, while thermodynamic analysis is used to evaluate the optimal dimensions and operating parameters. Finally, a numerical fluid mechanics and heat transfer model is used to predict the temperature field within the receiver. Important lessons from the modeling efforts are given, and their impacts on the design of a prototype are discussed.

scholarly journals Modeling of additive height and numerical analysis of cooling parameters for aero blade remanufacturing

2021 ◽  
Vol 12 (2) ◽  
pp. 803-818
Author(s):  
Miao Gong ◽  
Shijie Dai ◽  
Tao Wang ◽  
Liwen Wang
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Cooling Effect ◽  
Transfer Model ◽  
Factors Affecting ◽  
Coupled Heat Transfer ◽  
Blade Repair ◽  
Geometric Morphology ◽  
The Mathematical Model

Abstract. Additive remanufacturing height and matching cooling parameters are the key factors affecting blade repair quality. First, the mathematical model of the single additive remanufacturing repair height and wire-feeding speed was established, the solution method was proposed and the numerical solution was obtained, and the validity of the model was verified by experiments. Then, based on the calculation results of a single additive remanufacturing repair, the geometric morphology of the cross section under double additive remanufacturing repair was analyzed, and the mathematical model was established. Second, based on the optimal parameters obtained by numerical analysis and the mathematical model, the fluid structure coupling heat transfer model of “blade fixture” for base channel cooling was established. The cooling effect of the typical section under different initial temperatures and different flow rates was calculated, and the coupled heat transfer in the process of blade remanufacturing was explained by the mechanism. Third, through the comparative analysis of the cooling effect, optimal cooling parameters of double additive remanufacturing repair were obtained, and the model of coupled heat flow was verified by experiment. The results showed that the mathematical model of additive remanufacturing height is effective for studying the thermal cycle and cooling effect of welding, and the cooling parameters obtained by numerical analysis can effectively guarantee the quality of double additive remanufacturing of blade repair.

Influence of Continuous Direct Current on the Microtube Hydroforming Process

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Scott W. Wagner ◽  
Kenny Ng ◽  
William J. Emblom ◽  
Jaime A. Camelio
Keyword(s):  
High Pressures ◽  
Tube Hydroforming ◽  
Electrical Current ◽  
Deformation Energy ◽  
Recrystallization Temperature ◽  
Machining Processes ◽  
Electrically Assisted ◽  
Stainless Steel 304 ◽  
Hydroforming Process ◽  
Electrically Assisted Manufacturing

Research of the microtube hydroforming (MTHF) process is being investigated for potential medical and fuel cell applications. This is largely due to the fact that at the macroscale the tube hydroforming (THF) process, like most metal forming processes, has realized many advantages, especially when comparing products made using traditional machining processes. Unfortunately, relatively large forces compared to part size and high pressures are required to form the parts so the potential exists to create failed or defective parts. One method to reduce the forces and pressures during MTHF is to incorporate electrically assisted manufacturing (EAM) and electrically assisted forming (EAF) into the MTHF. The intent of both EAM and EAF is to use electrical current to lower the required deformation energy and increase the metal's formability. To reduce the required deformation energy, the applied electricity produces localized heating in the material in order to lower the material's yield stress. In many cases, the previous work has shown that EAF and EAM have resulted in metals being formed further than conventional forming methods alone without sacrificing the strength or ductility. Tests were performed using “as received” and annealed stainless steel 304 tubing. Results shown in this paper indicate that the ultimate tensile strength and bust pressures decrease with increased current while using EAM during MTHF. It was also shown that at high currents the microtubes experienced higher temperatures but were still well below the recrystallization temperature.

Effective Thermal Conductivity of Stainless Steel Fiber Sintered Felt With Honeycombed Channels

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Zhenping Wan ◽  
Xiaowu Wang ◽  
Shuiping Zou ◽  
Jun Deng
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stainless Steel ◽  
Steel Fiber ◽  
Transfer Model ◽  
Channel Diameter ◽  
Equivalent Thermal Conductivity ◽  
Axial Temperature ◽  
Stainless Steel Fiber ◽  
Radial Heat

Abstract A novel stainless steel fiber sintered felt (SSFSF) with honeycombed channels (SSFSFHC) is a promising support for catalytic combustion of the volatile organic compounds (VOCs). The SSFSFHC consists of stainless steel fiber, three-dimensionally reticulated porous structures, and interconnected honeycombed channels. The equivalent thermal conductivity (ETC) of the SSFSFHC is tested. It is found that the ETC of the SSFSFHC increases with the hot side temperature increasing but decreases with the porosity increasing and channel occupied area ratio increasing. The ETC of the SSFSFHC changes little with channel diameter increasing. The heat transfer model of the SSFSFHC is considered as parallel/series combinations of relevant thermal resistances. In order to estimate the ETC of the SSFSFHC, the correlation of the ETC of the SSFSF is derived. The expressions of the axial temperature under different porosities are deduced when eliminating the radial heat transfer between the channel section and the SSFSF section. The relationships of the transferred heats and the corresponding resistances along the radial direction are obtained by assuming that the radial heat transfer can be simplified as a serial of heat resistances located between the channels and the SSFSF.

scholarly journals Modeling of a Solar Receiver for Superheating Sulfuric Acid

2015 ◽  
Author(s):  
Justin L. Lapp ◽  
Alejandro Guerra-Niehoff ◽  
Hans-Peter Streber ◽  
Dennis Thomey ◽  
Martin Roeb ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Sulfuric Acid ◽  
Thermodynamic Analysis ◽  
Sulfur Cycle ◽  
Transfer Model ◽  
Modeling And Analysis ◽  
Concentrated Solar Energy ◽  
And Performance ◽  
Solar Receiver ◽  
Individual Design

A volumetric solar receiver for superheating evaporated sulfuric acid is developed as part of a 100kW pilot plant for the Hybrid Sulfur Cycle. The receiver, which uses silicon carbide foam as a heat transfer medium, heats evaporated sulfuric acid using concentrated solar energy to temperatures up to 1000 °C, which are required for the downstream catalytic reaction to split sulfur trioxide into oxygen and sulfur dioxide. Multiple approaches to modeling and analysis of the receiver are performed to design the prototype. Focused numerical modeling and thermodynamic analysis are applied to answer individual design and performance questions. Numerical simulations focused on fluid flow are used to determine the best arrangement of inlets, while thermodynamic analysis is used to evaluate the optimal dimensions and operating parameters. Finally a numerical fluid mechanics and heat transfer model is used to predict the temperature field within the receiver. Important lessons from the modeling efforts are given and their impacts on the design of a prototype are discussed.

scholarly journals Establishing Boundary Conditions Considering Influence Factors of the Room Equipped with a Ceiling Radiant Cooling Panel

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1684 ◽  
Author(s):  
Sang-Hoon Park ◽  
Dong-Woo Kim ◽  
Goo-Sang Joe ◽  
Seong-Ryong Ryu ◽  
Myoung-Souk Yeo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Simulation Model ◽  
Influence Factors ◽  
Cooling Capacity ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Factors Affecting ◽  
Various Boundary Conditions ◽  
Radiant Cooling

The objective of this study is to establish boundary conditions to evaluate the cooling capacity of the Cooling Radiant Ceiling Panel (CRCP) considering the environment of a room equipped with the CRCP. The current study investigated the boundary conditions and derivation techniques from previous studies. Based on the results of the analysis, a heat transfer model was derived for a room fitted with CRCP. In addition, the heat transfer model was used to derive the factors affecting the cooling capacity of the CRCP and each factor was simulated and verified through this model. The effects of these factors on the capacity of the CRCP was established by using various boundary conditions. To verify the validity of the simulation model, the experimental results were compared with the cooling capacity for a specific case. As a result, it was established that even for the same panel, there was a variance in the cooling capacity of the CRCP based on the boundary conditions and that the influence of the surface exposed to the outdoors had more implications. Consequently, this study presents the influence factors to be considered when designing CRCP.

Effect of Applied Electricity on Springback During Bending and Flattening of 304/316 Stainless Steel, Titanium AMS-T-9046 and Magnesium AZ31B

2016 ◽  
Author(s):  
Jacklyn Niebauer ◽  
Tyler Grimm ◽  
Derek Shaffer ◽  
Ian Sweeney ◽  
Ihab Ragai ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Strength ◽  
Electrical Current ◽  
Applied Loading ◽  
Stainless Steel 304 ◽  
Additional Testing ◽  
Specialized Equipment ◽  
Current Densities ◽  
Time And Energy ◽  
Electrically Assisted Manufacturing

One of the major issues with forming sheet metal is the tendency for parts to spring back towards their original shape when the applied loading is released. Springback is a form of geometric inaccuracy and is the result of residual stresses, which are created as the part deforms. As a result, forming intricate parts require specialized equipment and calculations to compensate for springback. Transportation industries that rely on forming high strength parts currently use complicated machinery that takes up time and energy to meet specifications. This research investigates the effects of electrically assisted manufacturing (EAM), a process in which electrical current is applied while a material is being manufactured, on springback. Bending and flattening testing will be performed on 4 metals: stainless steel 304 and 316, ASM-T-9046 titanium, and AZ31B magnesium. Additional testing will be performed on stainless steel, observing the effect of changing thicknesses, pulse durations, and current densities on springback. It was observed that an increase in pulse durations results in decreased springback for all the materials. Applying electricity to decrease springback was more effective for bending than flattening procedures in stainless steel and titanium, though it was equally effective for magnesium. For the additional testing on stainless steel, a change in thickness affected results when comparing it to current density, but not when observing similar applied current.

Sign in / Sign up

Export Citation Format

Share Document