Search results

This paper aims to study the heat transfer phenomenon occurring between heated walls and impinging fuel, showing the strict relationship between cooling effect after impingement and enhancing of wallfilm formation. The study focuses on a fundamental task in terms of pollutant emissions in internal combustion engines, aiming at giving a major contribution to the optimization of energy conversion systems in terms of environmental impact.

The paper is based on experimental campaigns relevant at taking measurements of an impinging spray over a heated wall in a confined vessel. The results, in both qualitative and quantitative terms (measurements of liquid and vapour radial penetration and thickness), are numerically reproduced by a computational model based on a Reynolds Averaged Navier Stokes approach, properly validated through customized sub-models.

The paper provides quantitative results about the agreement between radial penetration and vapour thickness between measurements and simulation, achieved by taking into account the cooling effect determined by the fuel impingement. This validation of the numerical model allows the author to give more considerations about the link between wall temperature and wallfilm formation.

This paper presents an original approach for the simulation of wall heat transfer, by imposing a boundary condition at the wall that may consider the heat conduction and temperature cooling given by fuel impingement in both lateral and normal directions. The classical Dirichlet boundary condition, characterized by imposing a fixed temperature value, is, instead, replaced by an approach based on calculating the unsteady process that couples the heat fluxes between the fluid and the solid material and within the solid itself.

Online offerings for transformative services create value for consumers, although little research examines the process through which these services deliver this value. The purpose of this paper is to develop a comprehensive framework to capture the complexity of the co-creation of transformative value experienced by the consumers of online transformative services.

This paper uses a netnography approach to examine longitudinal data from an online weight management program. In total, this research examines 15,304 posts from 3,149 users, including eight staff users.

Consumers integrate a range of social support resources, from informational support to esteem support, which provide a range of benefits such as new ideas and self-efficacy that underpin the different types of value such as epistemic and personal value. The degree of co-created value differs across the consumption experience but culminates over time into transformative value.

The proposed framework may be useful beyond the weight management and online contexts; however, further work is required in a range of behavioral contexts and other modes of service delivery.

By understanding the resources consumers integrate and value, co-created services can develop appropriate value propositions to assist in improving consumers’ well-being.

This research provides a comprehensive framework of the transformative value co-creation process, extending on existing frameworks which examine either the process, value co-creation or the types of value co-created.