Direct and flexible mesh contour coupling for airfoil optimisation

Blade profiles are used in many technical systems, including in the use of wind and water energy, and in aviation and shipping. The shape of the airfoil contour has a crucial influence on the resulting forces at the cross-section around the airfoil. The optimisation tasks are characterised by an exceptionally large number and dynamics of the influencing parameters. These are generated by a combined flow-related and structural mechanical simulation. The current research presented here takes up these core elements of the shaping processes and makes them more flexible and transparent than conventional design methodologies. The aim is to improve the design process through a direct and flexible mesh-contour coupling in such a way that the resulting shape change can be directly correlated to the initiating characteristic flow variable. The integration of the FEMSeq method enables the optimal distribution and reduction of the material without causing a failure of the overall structure.

Transient performance of the mixed flow and radial flow variable geometry turbines for an automotive turbocharger

In our previous paper, the steady-state test results of a mixed flow turbine with variable nozzle vanes for a turbocharger are reported. In this paper, the transient response of the same mixed flow turbine along with that of a similarly sized radial flow turbine is presented. The turbine size is suitable for handling the flow capacity of the diesel engines with swept volume up to 1.5 L. The previous experimental test set up is modified by adding a quick-release valve – actuation system before the turbine inlet to obtain a transient response. The radial and mixed flow turbines are tested for different turbine inlet pressures and for various opening positions of the nozzle vanes while matching the turbine mass flow parameters between radial and mixed flow turbines. Typically at nozzle vane openings corresponding to 50% mass flow parameter and 1.5 bar (abs) pressure at the inlet to the turbine, the transient response time for the turbine with mixed flow variable nozzle vanes configuration is about 0.770 s, as compared to 0.858 s for the turbine with radial flow variable nozzle vanes configuration.

Acute Severe Asthma in Adolescent and Adult Patients: Current Perspectives on Assessment and Management

Asthma is a chronic airway inflammatory disease that is associated with variable expiratory flow, variable respiratory symptoms, and exacerbations which sometimes require hospitalization or may be fatal. It is not only patients with severe and poorly controlled asthma that are at risk for an acute severe exacerbation, but this has also been observed in patients with otherwise mild or moderate asthma. This review discusses current aspects on the pathogenesis and pathophysiology of acute severe asthma exacerbations and provides the current perspectives on the management of acute severe asthma attacks in the emergency department and the intensive care unit.

HUBUNGAN INFORMASI SILPA APBD DAN ARUS KAS DENGAN PENGANGGARAN BELANJA MODAL PADA PEMERINTAH DAERAH

This study aims to test and analyze the influence of the SiLPA APBD, Operating Cash Flow, Investment Cash Flow, funding cash flows on capital expenditure budgeting. The source of this research data is the district and city financial statements that exist in the NTT provincial government within a period of 5 years, from 2012-2016. This study uses 2 variables, namely independent and bound variables. The independent variable consists of SiLPA APBD information, Operating Cash Flow (CFO), Investment Cash Flow (CFI) and Funding Cash Flow (CFF), while the dependent variable consists of capital expenditure. The results of this study are that simultaneously the four independent variables have a significant effect on capital expenditure budgeting, partially the four independent variables also have a significant effect on capital expenditure budgeting and the most dominant is the CFI (X3) or Investment Cash Flow variable.

PENGARUH OPERATING CAPACITY, ARUS KAS OPERASI DAN BIAYA VARIABEL TERHADAP FINANCIAL DISTRESS PADA PERUSAHAAN MANUFAKTUR SUBSEKTOR TEXTIL DAN GARMENT YANG TERDAFTAR DI BURSA EFEK INDONESIA (BEI) TAHUN 2009-2016

This research aims to determine the influences of operating capacity, operating cash flow and variable cost to the possibility of companies experiencing financial distress. Currently, we can see the textile and garment industries, were all having profit descreased year by year. If its left constantly and continously, then the company will be at risk of facing financial distress condition. Financial distress is a condition that describes the downturn of corporate performance, so that they are having financial trouble full filling their short term liabilities. Population of this research are manufactured companies on textile and garment’s sectors listed on the Indonesian’s Stock Exchange 2009-2016 periods. By sampling defined with purposive sampling’s methods, there are 10 companies, selected as the research’s samples. And this research using regretions logistics analysis method on SPSS version 23. This research finally conclude that operating capacity significantly by positive having affects to the possibility of companies to suffer financial distress. Operating cash flow significantly by negative having affect to the possibility of companies to suffer financial distress and variable cost significantly by positive having affect to the possibility of companies to suffer financial distress. Keywords : operating capacity, operating cash flow, variable cost, financial distress.

A comparative study of the performance of the mixed flow and radial flow variable geometry turbines for an automotive turbocharger

A new design of a mixed flow variable geometry turbine is developed for the turbocharger used in diesel engines having the cylinder capacity from 1.0 to 1.5 L. An equivalent size radial flow variable geometry turbine is considered as the reference for the purpose of bench-marking. For both the radial and mixed flow turbines, turbocharger components are manufactured and a test rig is developed with them to carry out performance analysis. Steady-state turbine experiments are conducted with various openings of the nozzle vanes, turbine speeds, and expansion ratios. Typical performance parameters like turbine mass flow parameter, combined turbine efficiency, velocity ratio, and specific speed are compared for both mixed flow variable geometry turbine and radial flow variable geometry turbine. The typical value of combined turbine efficiency (defined as the product of isentropic efficiency and the mechanical efficiency) of the mixed flow variable geometry turbine is found to be about 25% higher than the radial flow variable geometry turbine at the same mass flow parameter of 1425 kg/s √K/bar m2 at an expansion ratio of 1.5. The velocity ratios at which the maximum combined turbine efficiency occurs are 0.78 and 0.825 for the mixed flow variable geometry turbine and radial flow variable geometry turbine, respectively. The values of turbine specific speed for the mixed flow variable geometry turbine and radial flow variable geometry turbine respectively are 0.88 and 0.73.