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This study aims to find the characteristics of supercritical airfoil in helicopter rotor blades for hovering phase using numerical analysis and the validation using experimental results.

Using numerical analysis in the forward phase of the helicopter, supercritical airfoil is compared with the conventional airfoil for the aerodynamic performance. The multiple reference frame method is used to produce the results for rotational analysis. A grid independence test was carried out, and validation was obtained using benchmark values from NASA data.

From the analysis results, a supercritical airfoil in hovering flight analysis proved that the NASA SC rotor produces 25% at 5°, 26% at 12° and 32% better thrust at 8° of collective pitch than the HH02 rotor. Helicopter performance parameters are also calculated based on momentum theory. Theoretical calculations prove that the NASA SC rotor is better than the HH02 rotor. The results of helicopter performance prove that the NASA SC rotor provides better aerodynamic efficiency than the HH02 rotor.

The novelty of the paper is it proved the aerodynamic performance of supercritical airfoil is performing better than the HH02 airfoil. The results are validated with the experimental values and theoretical calculations from the momentum theory.

The sandy environment is one of the typical environments in which helicopters operate. Air-sand two-phase flow in sandy environments may be an important factor affecting flight safety. Taking a typical example, this paper aims to investigate the aerodynamic and rotor trim characteristics of the UH-60 helicopter in sandy environments.

A computational study is conducted to simulate the air-sand flow over airfoils based on the Euler–Lagrange framework. The simulation uses the S-A turbulence model and the two-way momentum coupling methodology. Additionally, the trim characteristics of the UH-60 rotor are calculated based on the isolated rotor trim algorithm.

The simulation results show that air-sand flow significantly affects the aerodynamic characteristics of the SC1095 airfoil and the SC1094R8 airfoil. The presence of sand particles leads to a decrease in lift and an increase in drag. The calculation results of the UH-60 helicopter rotor indicate that the thrust decreases and the torque increases in the sandy environment. To maintain a steady forward flight in sandy environments, it is necessary to increase the collective pitch and the longitudinal cyclic pitch.

In this paper, the aerodynamic characteristics of airfoils and the trim characteristics in the air-sand flow of the UH-60 helicopter are discussed, which might be a new view to analyse the impact of sandy environments on helicopter safety and manoeuvring.

This paper aims to present the jet mixing effectiveness of triangular tabs with semi-circular corrugations to control the subsonic and sonic correctly expanded jets.

Three semi-circular corrugated triangular tabs (Tab A, Tab B and Tab C) of equal blockage 5.11% are used, in which the corrugation locations on the tabs are varied. The offset distance between the semi-circular corrugations at the leaned edges of the triangular tabs are 0.0, 0.75 and 1.5 mm for the Tabs A, B and C, respectively. Two identical semi-circular corrugated tabs has been placed exactly 180° apart at the exit of the convergent nozzle. The pitot pressure measurements were taken to study the jet mixing characteristics of the tabs for the jet exit Mach numbers of 0.6, 0.8 and 1.0, and it is compared with the free jet.

The jet centerline pitot pressure decay reveals that, Tab A is very effective than Tab B and Tab C. For the jet exit Mach numbers of 0.6, 0.8 and 1.0, the potential core reduction for the Tab A is found to be 69.1%, 69.7% and 70.8%, respectively, when compared with the free jet.

The semi-circular corrugated triangular tabs were found to be more effective than the plain triangular tabs of equal blockage ratio for reducing the core length with minimum thrust loss.

The offset distance of the semi-circular corrugations are varied along the leaned sides of the triangular tabs, which is the novelty of this study.

In comparison to a nozzle with a larger/finite separation distance (Thanigaiarasu et al., 2019), a thin-lip nozzle (Srinivasarao et al., 2017) minimizes drag. Coaxial nozzles with thin lips are an appropriate tool for studying high subsonic jets because it does not create a dominant re-circulation zone. This study aims to analyze the characteristic of separation distances, between primary and secondary nozzles, within the range of 0.7–3.2 mm which can be considered a thin lip.

A separation distance of 0.7  (Papamoschou, 2004), 1.7  and 2.65 mm (Lovaraju and Rathakrishnan, 2011) is considered for the present study. The main nozzle exit Mach number is maintained at a subsonic condition of Mach 0.6, and the co-flowing nozzle exit Mach number is varied from 0% (secondary jet stopped/single jet) to 100% (Mach 0.6) in steps of 20% with respect to the main nozzle exit Mach number. A comparison was made between these velocity ratios for all three lip thicknesses in the present study. Design mesh and analysis were done by using Gambit 2.6.4 and Fluent 6.12. Velocity contours and turbulence contours were studied for qualitative analysis.

When lip thickness increases from 0.7 to 2.65 mm, the potential core length (PCL) of the primary jet decreases marginally. Additionally, the PCL of the primary jet elongates significantly as the velocity ratio increases. The primary shear layer is dominant at 20% co-flow (20 PCF), less dominant at 60% co-flow (60 PCF) and almost disappeared at 100% co-flow (100 PCF). Concurrently, the secondary shear layer almost disappeared in 20 PCF, dominant in 60 PCF and more dominant in 100 PCF. Different zones such as initial merging, intermediate and fully merged zones are quantitatively and qualitatively analyzed.

Co-flow nozzle is used in turbofan engine exhaust. The scaled-down model of a turbofan engine has been analyzed. Core length is directly proportional to the jet noise. The PCL signifies the jet noise reduction in a high-speed jet. For a low-velocity ratio, the potential core is reduced and hence can reduce the jet noise. At the same time, as the velocity ratio increases, the mass flow rate of the coaxial increases. The increase in the mass flow increases the thrust of the engine. The aircraft engine designer should analyze the requirement of the aircraft and choose the optimal velocity ratio coaxial nozzle for the engine exhaust (Papamoschou, 2004).

There have been many research studies carried out previously at various lip thickness such as 0.4  (Georgiadis, 2003), 0.7  (Papamoschou, 2004), 1.5  (Srinivasarao et al., 2014a), 1.7  (Sharma et al., 2008), 2  (Naren, Thanigaiarasu and Rathakrishnan, 2016), 2.65  (Lovaraju and Rathakrishnan, 2011), 3  (Inturiet al., 2022) and 3.2 mm (Perumal et al., 2020). However, there is no proper study to vary the lip thickness in this range from 0.7 to 3.2 mm to understand the flow behavior of a co-flowing jet.

To solve the shortcomings of existed search and rescue drones, search and rescue the trapped people trapped in earthquake ruins, underwater and avalanches quickly and accurately, this paper aims to propose a four-axis eight-rotor rescue unmanned aerial vehicle (UAV) which can carry a radar life detector. As the design of propeller is the key to the design of UAV, this paper mainly designs the propeller of the UAV at the present stage.

Based on the actual working conditions of UAVs, this paper preliminarily estimated the load of UAVs and the diameters of propellers and designed the main parameters of propellers according to the leaf element theory and momentum theory. Based on the low Reynolds number airfoil, this paper selected the airfoil with high lift drag ratio from the commonly used low Reynolds number airfoils. The chord length and twist angle of propeller blades were calculated according to the Wilson method and the maximum wind energy utilization coefficient and were optimized by the Asymptotic exponential function. The aerodynamic characteristics of the designed single propeller and coaxial propeller under different installation pitch angles and different installation distances were analyzed.

The results showed that the design of coaxial twin propellers can increase the load capacity by about 1.5 times without increasing the propeller diameter. When the installation distance between the two propellers was 8 cm and the tilt angle was 15° counterclockwise, the aerodynamic characteristics of the coaxial propeller were optimal.

The novelty of this work came from the conceptual design of the new rescue UAV and its numerical optimization using the Wilson method combined with the maximum wind energy utilization factor and the exponential function. The aerodynamic characteristics of the common shaft propeller were analyzed under different mounting angles and different mounting distances.

The purpose of this paper is to seek to propose that spiritual traditions of India have enormous wisdom to provide a wholesome spiritual foundation to the modern day management. It can also play a significant role in facilitating the dimensions of workplace spirituality as conceptualized by the western counterparts. The paper does not intend to reinvent the wheel but to present an integrated framework for facilitating workplace spirituality that incorporates the western and the Indian views.

For this study, the authors maintained an open approach. The authors first reviewed the extant literature on workplace spirituality to explore its dimensions. Thereafter, the authors searched for Indian spiritual traditions that can be suggested to have some similarity with the dimensions of workplace spirituality and can further help in facilitating those dimensions at the workplace.

The paper presents an integrated framework that suggests that doctrine of Karma Yoga, tradition of Loksangrah, Guna theory, daivi sampat and Pancha Kosha model can help in facilitating the five dimensions of workplace spirituality specified in the study.

The study proposes five dimensions of workplace spirituality which is not an exhaustive list. These dimensions may be facilitated by a variety of Indian spiritual traditions but this study includes only five specific Indian traditions.

The authors have creatively integrated the eastern and the western knowledge to come up with a framework that enriches the concept of workplace spirituality facilitation.

The purpose of this paper is to present multiple case studies of women in leadership roles in India with a view to identifying inhibitors, facilitators and the strategies adopted by them to mitigate the challenges in their odyssey to these positions. The paper contributes to the pivotal subject of under-representation of women in apex positions, which has garnered the attention of researchers in recent years grappling with the identification of the underlying causes. Thus, with a view to narrowing the gender gap in leadership positions, a greater understanding of this phenomenon is called for.

The paper adopts exploratory case study method using multiple case studies. Empirical data were gathered using in-depth semi-structured interviews and personality test (NEO FFI) from women in leadership positions. The qualitative data were analysed using thematic analysis.

The analysis of data has led to the identification of challenges faced by the women that were categorised as personal, professional, organisational and social issues. Further, six themes emerged as the strategies adopted by the women leaders to overcome the challenges. The paper also highlights the critical social, behavioural and organisational facilitators that played an important role in their leadership journey. The paper also includes context-specific findings of women leaders from Indian industry.

The paper would have relevance for researchers and practitioners in the field of gender diversity, leadership, organisational behaviour and human resource management. The findings of this paper can be leveraged by organisations to retain and manage female talent, which is a focal area in the present dynamic business environment, when a need for gender diversity is widely acknowledged by the top management in organisations. The exploratory case studies provide vistas for gender-based context-specific and cross-cultural research on the challenges faced by women executives in their leadership journey and the strategies adopted to mitigate these.

Though a great deal has been written about the barriers to women’s career advancement, less is known about the facilitators of women’s advancement. Also, women in the Asian context face unique challenges which present a major problem for multinational companies whose hopes for growth are pinned on emerging markets. The paper has identified new emergent themes, which have not been mentioned in the extant literature nationally or globally. The findings provide inputs to companies to adopt policies and practices to facilitate gender equality in leadership. The paper bridges the knowledge gap and makes conceptual contributions for future research.

Milk is often referred to as the ultimate food because it meets the nutritional needs of infants, children and adults alike. It is a rich source of protein, fat, sweetness, vitamins and minerals. Because of its widespread usage as a healthy dairy product, the issue of milk adulteration is of global significance. The increasing frequency of fraudulent methods in the dairy business raises concerns about its purity and quality.

A study was conducted and reviewed that looked at several approaches for detecting milk adulteration during the past 15 years. This study examines the current state of research and analyzes recent advances in development.

There are ways and technology available that can effectively put an end to the abhorrent practice of milk adulteration.

This research takes a unique approach, focusing on the application of milk adulteration. It provides an overview of milk adulteration detection and investigates the effectiveness of biosensors in identifying common milk adulterants.