| 1. |
- Berthelsen, Berthelsen, et al.
(författare)
-
Efficient Simulation of Nonlinear Heat Transfer during Thermal Spraying of Complex Workpieces
- 2014
-
Ingår i: World Journal of Mechanics. - : Scientific Research Publishing, Inc.. - 2160-049X .- 2160-0503. ; 4:9, s. 289-301
-
Tidskriftsartikel (refereegranskat)abstract
- The quality of coatings, produced by thermal spraying processes, considerably decreases with the occurrence of higher residual stresses, which are especially pronounced for complex workpiece geometries. To understand the occurring effects and to aid in the planning of coating processes, simulations of the highly transient energy flux of the HVOF spray gun into the substrate are of great value. In this article, a software framework for the simulation of nonlinear heat transfer during (HVOF) thermal spraying is presented. One part of this framework employs an efficient GPU-based simulation algorithm to compute the time-dependent input boundary conditions for a spray gun that moves along a complex workpiece of arbitrary shape. The other part employs a finite-element model for a rigid heat conductor adhering to the computed boundary conditions. The model is derived from the fundamental equations of continuum thermodynamics where nonlinear temperature-depending heat conduction is assumed.
|
|
| 2. |
- Bin Asad, S M Sayeed, et al.
(författare)
-
A Review of Particle Image Velocimetry for Fish Migration
- 2016
-
Ingår i: World Journal of Mechanics. - : Scientific Research Publishing, Inc.. - 2160-049X .- 2160-0503. ; 6:4, s. 131-149
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the flow characteristic in fishways is crucial for efficient fish migration. Flow characteristic measurements can generally provide quantitative information of velocity distributions in such passages; Particle Image Velocimetry (PIV) has become one of the most versatile techniques to disclose flow fields in general and in fishways, in particular. This paper firstly gives an overview of fish migration along with fish ladders and then the application of PIV measurements on the fish migration process. The overview shows that the quantitative and detailed turbulent flow information in fish ladders obtained by PIV is critical for analyzing turbulent properties andvalidating numerical results.
|
|
| 3. |
- Halldin, Anders, 1971, et al.
(författare)
-
On a Constitutive Material Model to Capture Time Dependent Behaviour of Cortical Bone
- 2014
-
Ingår i: World Journal of Mechanics. - : Scientific Research Publishing, Inc.. - 2160-049X .- 2160-0503. ; 4:11, s. 348-361
-
Tidskriftsartikel (refereegranskat)abstract
- It is commonly known that cortical bone exhibits viscoelastic-viscoplastic behavior which affects the biomechanical response when an implant is subjected to an external load. In addition, long term effects such as creep, relaxation and remodeling affect the success of the implant over time. Constitutive material models are commonly derived from data obtained in in vitro experiments. However during function, remodeling of bone greatly affects the bone material over time. Hence it is essential to include long term in vivo effects in a constitutive model of bone. This paper proposes a constitutive material model for cortical bone incorporating viscoelasticity, viscoplasticity, creep and remodeling to predict stress-strain at various strain rates as well as the behavior of bone over time in vivo. The rheological model and its parameters explain the behavior of bone subjected to longitudinal loading. By a proper set of model parameters, for a specific cortical bone, the present model can be used for prediction of the behavior of this bone under specific loading conditions. In addition simulation with the proposed model demonstrates excellent agreement to in vitro and in vivo experimental results in the literature.
|
|
| 4. |
- Höller, J. Bastian, et al.
(författare)
-
Integrating Downstream Ecological, Social and Economic Effects of Hydropower to Hydraulic Modeling: A Review
- 2023
-
Ingår i: World Journal of Mechanics. - 2160-049X .- 2160-0503. ; 13:8, s. 149-172
-
Forskningsöversikt (refereegranskat)abstract
- Hydropower gains increasing importance as a steerable and controllable power source in a renewable energy mix and deregulated markets. Although hydropower produces fossil-free energy, it has a significant impact on the local environment. This review investigates the effects of flow alterations by hydropower on the downstream river system and the possibilities to integrate these effects into hydraulic modeling. The results show that various effects of flow regulation on the ecosystem, but also social and economic effects on related communities were observed in the last decades. The application of hydraulic models for investigations of ecological effects is common. Especially hydraulic effects and effects on fish were extensively modeled with the help of hydraulic 1D- and 2D-simulations. Current applications to investigate social and economic effects integrated into hydraulic modeling are meanwhile limited. Approaches to realizing this integration are presented. Further research on the economic valuation of ecosystems and integration of social and economic effects to hydraulic models is necessary to develop holistic tools to support decision-making on sustainable hydropower.
|
|
