Olaf Meyer

Numerical investigation of alternative process conditions for influencing the thermal history of spray deposited billets

Abstract In spray forming, during the spray deposition process and the subsequent cooling period a time dependent temperature field develops within the product and the solidification of the remaining liquid fraction takes place. In this paper, the time dependent thermal conditions and solidification behaviour in spray formed billets are investigated. A transient numerical simulation is carried out and compared with experimental results. A description of the relevant model and the developed program will be given and an investigation of the influence of different process parameters on the time dependent temperature field and the solidification history within billets are shown. The numerical model is based on a single-phase formulation of the energy equation. A non-orthogonal coordinate system is used for grid generation within the time dependent growing shape of the billet. Temperature measurements are carried out within the substrate and also in the lower part of the billet in the spray forming process. The material discussed throughout this contribution is CuSn6 (2.1020).

Convective heat transfer from a billet due to an oblique impinging circular jet within the spray forming process

Abstract An experimental investigation was performed to study the heat transfer process from the surface of a billet due to an oblique impinging circular gas jet. The gas stream was generated by a circular array of 24 single jets within an atomizer nozzle. The application of this heat transfer condition can be found in the spray forming process during the cooling of the sprayed billet. At several positions on the billet surface the local heat transfer coefficients were measured. The measurement technique was based on the cooling of a surface mounted sensor having a sufficiently small Biot number. A comparison between published data and a test case had been carried out successfully. The distance between the atomizer and the billet, the gas mass flow rate, and the rotation angle of the billet were varied. Velocity measurements were executed to characterise the gas flow in the confined jet in the absence of the billet, while numerical flow field simulations were used to calculate the flow around the billet. The heat transfer coefficient distribution showed a significant peak at the stagnation point and decreased with increasing atomizer to billet distance and also with decreasing gas mass flow. The heat transfer coefficients averaged over the circumference of the billet were correlated empirically.

The Impact of Corruption on International Commercial Contracts – General Report

Corruption is recognized as one of the major obstacles to the development of international trade today. There seems to be consensus that curbing corruption is a task too big to be met by criminal law alone and that other branches of law have to contribute their part as well. Thus, where contracts are tainted with corruption, there are genuine issues of contract law at stake that need to be decided with a view to effectively protecting victims and at the same time deterring potential wrongdoers. In this report, we shall take a look at contracts providing for bribery as well as the contracts that have been procured by the payment of bribes. The analysis is tailored toward commercial contracts, including also contracts with state-owned enterprises. It shows that, interestingly, different jurisdictions have taken quite different approaches as to whether these contracts can be enforced in court. A second though related problem is whether the wrongdoers, after they have performed their part of the deal, should be punished by denying them restitutionary remedies for their investment.

The impact of corruption on international commercial contracts

Corruption is recognized as one of the major obstacles to the development of international trade today. There seems to be consensus that curbing corruption is a task too big to be discharged by criminal law alone and that other branches of law have to contribute their part as well. Thus, where contracts are tainted with corruption, there are genuine issues of contract law at stake that need to be decided with a view to effectively protecting victims and at the same time deterring potential wrongdoers. In this report, we shall take a look at contracts providing for bribery as well as contracts that have been procured by the payment of bribes. The analysis is tailored toward commercial contracts, including also contracts with state-owned enterprises. It shows that, interestingly, different jurisdictions have taken quite different approaches as to whether these contracts can be enforced in court. A second, though related, problem is whether the wrongdoers, after they have performed their part of the deal, should be punished by denying them restitutionary remedies for their investment.

European perspectives on producers' liability: Direct Producers' Liability for Non-conformity and the Sellers' Right of Redress

The Consumer Sales Directive has to a large extent harmonised the consumer’s rights and remedies against professional sellers. As a next step, the European Commission now favours the introduction of an EU wide direct producers’ liability. Currently, the situation in Europe is divided: Whereas in most jurisdictions consumers can only bring claims against their sellers, a growing number of countries recognise a direct claim of the consumer or final buyer against the producer.This book compiles national reports from more than 20 European countries on the consumer’s remedies for non-conforming goods and the fi nal seller’s right of redress. Additional contributions approach this topic from the perspectives of law and economics, legal history, and behavioural psychology. A comprehensive introductory chapter provides a comparative report on thedifferent models of producers’ liability, including their impact on the internal market, and sets out elements for further harmonisation.