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The design of main rotor blade tips is of interest to helicopter manufactures since the tip details affect the performance and acoustics of the rotor. The paper aims to discuss this issue.

In this paper, computation fluid dynamics is used to simulate the flow around hovering helicopter blades with different tip designs. For each type of blade tip a parametric study on the shape is also conducted for comparison calculations were performed the constant rotor thrust condition. The collective pitch and the cone angles of the blades were determined by at an iterative trimming process.

Analysis of the distributed blade loads shows that the tip geometry has a significant influence on aerodynamics and aeroacoustics especially for stations where blade loading is high.

The aeroacoustic characteristics of the rotors were obtained using Ffowcs Williams-Hawkings equations.

This paper aims to explore the potential of transition prediction methods for modelling transitional shock wave/boundary layer interactions. The study is fuelled by the strong interest of researchers and airframe manufacturers in reducing the drag of vehicles flying at transonic speeds. The principle of drag reduction via flow laminarity is valid, provided there is no need for the flow to sustain large pressure gradients or shocks. This is true, as laminar boundary layers are less resistant to flow separation.

It is, therefore, worthwhile to assess the performance of CFD methods in modelling laminar boundary layers that can be tripped to turbulent just before an interaction with a shock. In this work, the CFD solver of Liverpool University is used. The method is strongly implicit, and, for this reason, the implementation of intermittency-based models requires special attention. The Navier–Stokes equations, the transport equations of the kinetic energy of turbulence and the turbulent frequency are inverted at the same time as the transport equations for the flow intermittency and the momentum thickness Reynolds number.

The result is stable and robust convergence even for complex three-dimensional flow cases. The method is demonstrated for the flow around the V2C section of the TFAST EU, F7 project. The results suggest that the intermittency-based model captures the fundamental physics of the interaction, but verification and validation are needed to ensure that accurate results can be obtained. For this reason, comparisons with the TFAST experiments is put forward as a means of establishing confidence in the transition prediction tools used for shock/boundary layer interaction simulation.

At the moment, experimental data for transonic transitional buffet are not yet available, although this will change in the near future.

The required CPU time is neither insignificant not prohibitive for routine computations.

Reducing aircraft drag without compromising on stall characteristics will result in lower fuel consumption and contribute to a greener and more economic flight for passengers.

To the authors’ knowledge, this is the first time that transitional buffet has been addressed.

The purpose of this paper is to provide an empirical evidence concerning the influence of Corporate governance and voluntary disclosures in annual reports: a post-International Financial Reporting Standards adoption evidence from an emerging capital market.

Data were collected from the annual reports of all 22 listed non-financial firms over a five-year period. Using content analysis, the audited annual reports of the firms were scored on the extent of overall and four specific types of voluntary disclosures made. The panel data obtained were analyzed using a generalized ordinary least squares regression model.

The findings of the study show that voluntary disclosures among the firms are low even after the adoption of IFRS. Corporate governance attributes of board size and board leadership structure are significant determinants of the extent of voluntary disclosures made by the firms. However, board independence and auditor type exhibit only a significant positive effect on voluntary financial and forward-looking information disclosures.

Firms’ voluntary information disclosure and governance variables were restricted to those in annual reports, which may partially reflect the reality of firms’ disclosure and governance practices.

The present study offers useful insights to regulators of the capital market to strengthen monitoring of firms to ensure strict adherence to corporate governance best practice guidelines as a means of improving information environment.

This study is one of the very few ones in Africa, especially in the context of Ghana Stock Exchange, to use post-IFRS data and examine a disaggregated voluntary disclosure by firms.

This paper aims to investigate corporate internet reporting (CIR) by Kenyan and Tanzanian listed companies and whether the level of CIR is related to corporate governance structures.

The authors collect data over a four-year period from companies listed on the Nairobi Securities Exchange and the Dar es Salaam Securities Exchange. Panel data models (random effects) are used for the analysis.

The results indicate that the level of CIR in both countries is high, but the highest in Kenya. The authors find that CIR increases with foreign ownership, audit committee independence and financial expertise but decreases with domestic ownership concentration. They also show that the effects of ownership concentration are moderated by country-specific factors. Overall, the results demonstrate that effective governance structures may lead to higher levels CIR in sub-Saharan Africans.

This study extends, as well as contributes to the existing literature by the examining the corporate governance-disclosure nexus relating to CIR in sub-Saharan Africa. These findings have policy implications for African countries looking to attract foreign investment.

Using the resource dependence and legitimacy theories, this research aims to examine the relationship between board attributes and human rights reporting, as well as the interaction effect of board chairperson experience on the relationship among listed firms at the Nairobi Securities Exchange (NSE).

This study collected data from annual reports of firms listed on the NSE from 2009 to 2019 using content analysis to examine how boards influence human rights reporting. A total of 547 firm-year observations were used to test the hypotheses. This study used a hierarchical regression model to examine the relationship.

This study found that board attributes are important predictors of human rights reporting. This study shows that both board diversity and board independence have a positive impact on human rights reporting. Furthermore, the interaction results revealed that having a highly experienced chairperson strengthens the effect of board independence on human rights reporting; however, this study found that experienced chairperson reduces the influence of board diversity on human rights reporting.

The findings suggest that board diversity and independence are essential attributes to which listed companies should pay attention when appointing board members. Moreover, the chairperson's leadership on the board is critical in ensuring that publicly trading companies adopt policies that disclose human rights information.

This paper provides insights into Kenya's human rights disclosure practices. It also analyzes how boards influence human rights disclosures, an empirical test that has received little attention in the previous literature. This study emphasizes the importance of board members and the chairperson in advocating for human rights reporting to improve corporate sustainability.

This study aims to examine the effects of board structures (BS) on the financial performance and stability of banks in Africa.

Using annual data of 366 banks from 26 African countries from 2007 to 2015, the study estimates growths in financial performance using net interest margin and risk-adjusted return on assets; bank stability using z-scores; and BS using board size, board independence and board gender diversity. The system generalized method of moments and ordinary least squares panel-corrected standard error estimation strategies are used to estimate panel regressions.

The study concludes that board independence has a negative and significant relationship with financial stability but has diverse relationships with financial performance. Board size and board gender diversity have insignificant relationships with financial performance and stability.

The study has relevant implications for practitioners, policymakers and the academic community. The findings provide evidence of the extent to which BS have been instituted to influence the financial profitability and stability of banks in Africa.

This study offers robust evidence on the role of BS in the performance and stability of banks; using a multidimensional conceptualization of the performance and stability of banks in 26 countries in Africa.

The purpose of this paper is to investigate the potential influence of corporate governance mechanisms on risk disclosure quality in Tunisia.

The authors examine 152 annual reports of Tunisian non-financial-listed firms during 2008–2013, and use the manual content analysis method to measure the risk disclosure quality.

The authors find that the quality of risk disclosure in Tunisian companies is relatively low, and also find that the quality of risk disclosure is positively associated with institutional ownership, board independence, the presence of women on the board, the presence of family members on the board and the independence of audit committee. Managerial ownership has a negative effect on risk disclosure quality. Finally, the authors find that the revolution decreases the influence of concentration ownership, government ownership, family ownership and audit committee size on risk disclosure quality.

Using a comprehensive set of corporate governance mechanisms and a new measure for risk disclosure quality in Tunisia, the authors provide the first empirical evidence on the impact of corporate governance mechanisms on risk disclosure quality in a developing country. The study has theoretical and practical implications for both developed and developing countries.

This study aims to examine the relationship between corporate governance (CG) voluntary disclosure (VD) and firm valuation (FV). Moreover, the study also investigates whether VD mediates the impact of CG on FV or not.

The study is based on a panel data set of top 100 listed firms on Bombay Stock Exchange (BSE) over the period of 2014–2018 and develops CG index and VD index (VDI) in order to capture both the constructs respectively. The author adopts suitable panel data model to examine the relationship between CG, VD and FV as well as indirect impact of CG on FV through mediation of VD. Further, the author uses instrumental variables regression model for robustness check.

The author's findings reveal significant positive impact of CG on FV. Likewise, VD also exhibits significant positive impact on FV. Notably, the interaction of CG and VD complements each other in making positive contribution towards FV. In addition, the author observes that VD partially mediates the impact of CG on FV. Specifically, the outcome suggests that CG apart from having direct impact on FV also influences the same through the mediation of VD. Moreover, as the direction of indirect impact coincide with direct impact, such indirect impact has complementary relationship with the direct impact, implying that when CG makes direct contribution towards improving FV, CG's contribution toward FV through mediation of VD also increases.

To the best of the author's knowledge, this is the first endeavor in the extant literature that examines the interaction performance impact of CG and VD. Further, the author also provides primary evidence on the mediating impact of VD in the relationship between CG and FV.

The purpose of this study is to review the prior empirical studies that investigate the corporate governance (CG) determinants and provide a synopsis, and explore the main factors that drive the level of CG disclosure in the Greek context.

The authors perform an extensive review of the relevant literature and identify 24 papers that use various potential factors. Afterwards, the authors construct two different GC indices to investigate these potentials, and the authors conduct multiple regression analysis to identify and explain these determinants.

The empirical analysis shows that large Greek listed firms are more likely to disclose more CG information in the CG statement. In addition, the analysis shows statistically significant association with performance-related variables (such as Tobin’s Q and liquidity) and CG-related variables (such as independent members, board meetings and women on board).

The results of the study support theoretical arguments that Greek listed firms disclose CG information not only to fulfill task-related requirements but also to be perceived as social and legitimate.

To the best of the authors’ knowledge, this is the first study that provides a synopsis of the prior literature in CG determinants, while it goes one step further by using the majority of the potential factors that have been used so far. Moreover, this study uses a multi-theoretical framework to address theoretical development, an approach that generates an outline of fruitful directions for future research.