Evaluating Regenerative Cooling Channels for Nuclear Thermal Propulsion with Additive Manufacturing

2022 ◽  
Author(s):  
William A. Mullin ◽  
Keaton Melendez ◽  
Benjamin Stefanko ◽  
Aaron Bell ◽  
Grant Davis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Regenerative Cooling ◽  
Cooling Channels

Fabrication of circular cooling channels by cold metal transfer based wire and arc additive manufacturing

2021 ◽  
pp. 095440542199561
Author(s):  
Shaohua Han ◽  
Zhongzhong Zhang ◽  
Pengxiang Ruan ◽  
Shiwen Cheng ◽  
Dingqi Xue
Keyword(s):  
Additive Manufacturing ◽  
High Energy ◽  
Cooling Effect ◽  
High Deposition Rate ◽  
Cooling Channel ◽  
Conformal Cooling Channel ◽  
Conformal Cooling ◽  
Energy Beam ◽  
Cooling Channels ◽  
Straight Line

Additive manufacturing has been proven to be a promising technology for fabricating high-performance dies, molds, and conformal cooling channels. As one of the manufacturing methods, wire and arc additive manufacturing displays unique advantages of low cost and high deposition rate that are better than other high energy beam-based ones. This paper presents a preliminary study of fabricating integrated cooling channels by CMT-based wire and arc additive manufacturing process. The deposition strategies for fabricating circular cross-sectional cooling channels both in conformal and straight-line patterns have been investigated. It included optimizing the welding torch angle, fabricating the enclosed semicircle structure and predicting the collision between the torch and constructed part. The cooling effect test was also conducted on both the conformal cooling channel and straight-line cooling channel. The results affirmed a higher cooling efficiency and better uniform cooling effect of the conformal cooling channel than straight-line cooling channel.

Topology Optimization of Serpentine Channels for Minimization of Pressure Loss and Maximization of Heat Transfer Performance As Applied for Additive Manufacturing

2019 ◽  
Author(s):  
Shinjan Ghosh ◽  
Jayanta S. Kapat
Keyword(s):  
Heat Transfer ◽  
Topology Optimization ◽  
Additive Manufacturing ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Cooling Channels ◽  
Blade Cooling

Abstract Gas Turbine blade cooling is an important topic of research, as a high turbine inlet temperature (TIT) essentially means an increase in efficiency of gas turbine cycles. Internal cooling channels in gas turbine blades are key to the cooling and prevention of thermal failure of the material. Serpentine channels are a common feature in internal blade cooling. Optimization methods are often employed in the design of blade internal cooling channels to improve heat-transfer and reduce pressure drop. Topology optimization uses a variable porosity approach to manipulate flow geometries by adding or removing material. Such a method has been employed in the current work to modify the geometric configuration of a serpentine channel to improve total heat transferred and reduce the pressure drop. An in-house OpenFOAM solver has been used to create non-traditional geometries from two generic designs. Geometry-1 is a 2-D serpentine passage with an inlet and 4 bleeding holes as outlets for ejection into the trailing edge. Geometry-2 is a 3-D serpentine passage with an aspect ratio of 3:1 and consists of two 180-degree bends. The inlet velocity for both the geometries was used as 20 m/s. The governing equations employ a “Brinkman porosity parameter” to account for the porous cells in the flow domain. Results have shown a change in shape of the channel walls to enhance heat-transfer in the passage. Additive manufacturing can be employed to make such unconventional shapes.

scholarly journals Heat Transfer Prediction for Methane in Regenerative Cooling Channels with Neural Networks

2020 ◽  
Vol 34 (2) ◽  
pp. 347-357 ◽  
Author(s):  
G. Waxenegger-Wilfing ◽  
K. Dresia ◽  
J. C. Deeken ◽  
M. Oschwald
Keyword(s):  
Heat Transfer ◽  
Neural Networks ◽  
Regenerative Cooling ◽  
Cooling Channels

Smart Structure Integration Through Ultrasonic Additive Manufacturing

2014 ◽  
Author(s):  
Marcelo J. Dapino
Keyword(s):  
Additive Manufacturing ◽  
Fiber Optics ◽  
Smart Materials ◽  
Smart Structure ◽  
Cnc Machining ◽  
Ultrasonic Power ◽  
Sensors And Actuators ◽  
Cooling Channels ◽  
Ultrasonic Additive Manufacturing ◽  
The Matrix

Ultrasonic additive manufacturing (UAM), a form of 3D printing based on ultrasonic metal welding, allows for room-temperature fabrication of adaptive structures with seamlessly embedded sensors and actuators. UAM combines solid-state welding of metallic foils, automated additive foil layering, and CNC machining. The most recent UAM systems utilize 9 kW of ultrasonic power for improved build strength and quality over low power systems, leading to previously unfeasible smart structures. Current UAM efforts in this area are focused on embedding smart materials, fiber optics, and cooling channels into metallic matrices. Since UAM process temperatures do not exceed one half of the melting temperature of the matrix, various alloys such as NiTi and FeGa, and polymers such as PVDF, have been successfully embedded without degradation of the smart material or the matrix. This paper aims to demonstrate the benefits of UAM, with particular emphasis on smart components for vehicle design. Example concepts include stiffness-tunable structures, thermally invariant composites, and materials with embedded cooling channels.

scholarly journals Pilot Demonstration of Hot Sheet Metal Forming Using 3D Printed Dies

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5695
Author(s):  
Jaume Pujante ◽  
Borja González ◽  
Eduard Garcia-Llamas
Keyword(s):  
Additive Manufacturing ◽  
Hot Spot ◽  
Hot Stamping ◽  
Design Strategies ◽  
Press Hardening ◽  
Cooling Channels ◽  
Plant Environment ◽  
Conformal Cooling Channels ◽  
3D Printed ◽  
Manufacturing Technologies

Since the popularization of press hardening in the early noughties, die and tooling systems have experienced considerable advances, with tool refrigeration as an important focus. However, it is still complicated to obtain homogeneous cooling and avoid hot spot issues in complex geometries. Additive Manufacturing allows designing cavities inside the material volume with little limitation in terms of channel intersection or bore entering and exit points. In this sense, this technology is a natural fit for obtaining surface-conforming cooling channels: an attractive prospect for refrigerated tools. This work describes a pilot experience in 3D-printed press hardening tools, comparing the performance of additive manufactured Maraging steel 1.2709 to conventional wrought hot work tool steel H13 on two different metrics: durability and thermal performance. For the first, wear studies were performed in a controlled pilot plant environment after 800 hot stamping strokes in an omega tool configuration. On the second, a demonstrator tool based on a commercial tool with hot spot issues, was produced by 3D printing including surface-conformal cooling channels. This tool was then used in a pilot press hardening line, in which tool temperature was analyzed and compared to an equivalent tool produced by conventional means. Results show that the Additive Manufacturing technologies can be successfully applied to the production of press hardening dies, particularly in intricate geometries where new cooling channel design strategies offer a solution for hot spots and inhomogeneous thermal loads.

scholarly journals Integrated Optimum Layout of Conformal Cooling Channels and Optimal Injection Molding Process Parameters for Optical Lenses

2019 ◽  
Vol 9 (20) ◽  
pp. 4341 ◽  
Author(s):  
Chen-Yuan Chung
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Process Parameters ◽  
Large Diameter ◽  
Melt Temperature ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Highly Efficient ◽  
Conformal Cooling Channels ◽  
Filling Time

Plastic lenses are light and can be mass-produced. Large-diameter aspheric plastic lenses play a substantial role in the optical industry. Injection molding is a popular technology for plastic optical manufacturing because it can achieve a high production rate. Highly efficient cooling channels are required for obtaining a uniform temperature distribution in mold cavities. With the recent advent of laser additive manufacturing, highly efficient three-dimensional spiral channels can be realized for conformal cooling technique. However, the design of conformal cooling channels is very complex and requires optimization analyses. In this study, finite element analysis is combined with a gradient-based algorithm and robust genetic algorithm to determine the optimum layout of cooling channels. According to the simulation results, the use of conformal cooling channels can reduce the surface temperature difference of the melt, ejection time, and warpage. Moreover, the optimal process parameters (such as melt temperature, mold temperature, filling time, and packing time) obtained from the design of experiments improved the fringe pattern and eliminated the local variation of birefringence. Thus, this study indicates how the optical properties of plastic lenses can be improved. The major contribution of present proposed methods can be applied to a mold core containing the conformal cooling channels by metal additive manufacturing.

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