Experimental and numerical results of active flow control on a highly loaded stator cascade

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.This article presents experimental and numerical results for a compressor cascade with active flow control. Steady and pulsed blowing has been used to control the secondary flow and separation characteristics of a highly loaded controlled diffusion airfoil. Investigations were performed at the design incidence for blowing ratios from approximately 0.7 to 3.0 (jet-to-inlet velocity) and a Reynolds number of 840 000 (based on axial chord and inlet velocity). Detailed flow field data were collected using a five-hole pressure probe, pressure taps on the blade surfaces, and time-resolved Particle Image Velocimetry. Unsteady Reynolds-averaged Navier–Stokes simulations were performed for a wide range of flow control parameters. The experimental and numerical results are used to understand the interaction between the jet and the passage flow. The benefit of the flow control on the cascade performance is weighted against the costs of the actuation by introducing an efficiency which takes the presence of the jets into account.DFG, SFB 557, Beeinflussung komplexer turbulenter Scherströmunge

Industry 4.0 Visions and Reality- Status in Norway

Part 5: Industry 4.0 ImplementationsInternational audienceThe concept and vision of Industry 4.0 has been around for almost a decade and gain a lot of momentum and attraction globally. Central to the vision of Industry 4.0 is the concept of a “Cyber-Physical system”, linking the IT elements of an enterprise (Cyber) with the physical system (man and machine) of an enterprise. This vision is well known and promoted as crucial in radically transforming todays manufacturing industry. While there is a plethora of papers and studies of the various “cyber” aspects, the concept, visions, benefits as well as the downsides of Industry 4.0, few papers have much to say about the actual implementation. Based on a digital maturity mapping of ten front line manufacturing enterprises in Norway this paper analyses implementation at shop floor level of both cyber and physical system and their interaction. From the survey data a clear picture emerges of the development of a cyber system, as well as worker usage and benefit of the system. However, the two systems don’t interact very well, worker interaction is limited to plain old keyboard usage, instead of employing more mobile, handsfree, voice based or similar interaction methods. Currently there is no cyber-physical system, rather a burgeoning cyber system poorly linked to the physical world. If the cyber-physical system is to be realized there is a need for a rethinking and upgrading of man-machine interaction

Recruitment of histone methyltransferase Ehmt1 to Foxp3 TSDR counteracts differentiation of induced regulatory T cells

Differentiation towards CD4 + regulatory T (Treg) cells is essentially dependent on an epigenetic program at Treg signature genes, which involves remodeling of the Treg-specific demethylated regions (TSDRs). In particular, the epigenetic status of the conserved non-coding sequence 2 of Foxp3 (Foxp3 TSDR) determines expression stability of the master transcription factor and thus, Treg lineage identity. However, the molecular mechanisms controlling the epigenetic remodeling at TSDRs in Treg and conventional T (Tcon) cells are largely unknown. Using a combined approach of DNA pull-down and mass spectrometric analysis, we report a novel regulatory mechanism in which transcription factor Wiz recruits the histone methyltransferase Ehmt1 to Foxp3 TSDR. We show that both Wiz and Ehmt1 are crucial for shaping the region with the repressive histone modification H3K9me2 in conventional T cells. Consistently, knocking out either Ehmt1 or Wiz by CRISPR/Cas resulted in the loss of H3K9me2 and enhanced Foxp3 expression during iTreg differentiation. Moreover, the essential role of the Wiz–Ehmt1 interaction as observed at several TSDRs indicates a global function of Ehmt1 in the Treg differentiation program. Using a combined approach of DNA pull-down and mass spectrometric analysis, we report a novel regulatory mechanism in which transcription factor Wiz recruits the histone methyltransferase Ehmt1 to Foxp3 TSDR. We show that both, Wiz and Ehmt1 are crucial for shaping the region with the repressive histone modification H3K9me2 in Tcon cells. Consistently, knocking out either Ehmt1 or Wiz by CRISPR/Cas resulted in the loss of H3K9me2 and enhanced Foxp3 expression during iTreg differentiation. Moreover, the essential role of the Wiz-Ehmt1 interaction as observed at several TSDRs indicates a global function of Ehmt1 in the Treg differentiation program