APPROXIMATE FUNCTION FOR UNSTEADY AERODYNAMIC KERNEL FUNCTION OF AEROELASTIC LIFTING SURFACES

ABSTRACT: Prediction of unsteady aerodynamic loads is still the most challenging task in flutter aeroelastic analysis. Generally the numerical estimation of steady and unsteady aerodynamic of thin lifting surface is conducted based on an integral equation relating aerodynamic pressure and normal wash velocity. The present work attempts to increase the accuracy of the prediction by using an approximate approach to evaluate kernel function occurring in the integral equation in the form of cylindrical function.  Following previous approximation approach by other researchers to solve the cylindrical function for planar lifting surfaces, in the present work such approach is extended to non planar lifting surfaces.  To increase the accuracy of the method, the integration region of the kernel function is divided into two parts namely near and far regions, where a nonlinear regression curve fitting technique is adapted to approximate the denominator part of the cylindrical function of each region. ABSTRAK: Penelahan daya aerodinamik tidak stabil merupakan satu tugas yang mencabar dalam menganalisis getaran aeroanjalan. Umumnya, anggaran berangka untuk daya aerodinamik stabil dan tidak stabil pada permukaan mengangkat yang nipis, adalah berdasarkan kepada persamaan kamiran di antara tekanan aerodinamik dan halaju aliran udara pada garis normal yang terhasil di bawah sayap pesawat. Kajian ini adalah bertujuan untuk menghasilkan penelahan daya aerodinamik yang lebih tepat dengan menggunakan pendekatan kira hampir untuk menilai fungsi Kernel yang terdapat dalam persamaan kamiran dalam bentuk fungsi silinder. Dengan menggunakan pendekatan kira hampir yang digunakan oleh penyelidik sebelumnya untuk menyelesaikan fungsi silinder pada permukaan mengangkat satah, kajian ini mengembangkan pendekatan tersebut kepada permukaan mengangkat tak sesatah. Untuk meningkatkan lagi ketepatan penelahan, kawasan pengamiran fungsi Kernel dibahagikan kepada dua bahagian, kawasan hampir dan kawasan jauh, di mana penyuaian lengkung regresi tak linear digunakan untuk kiraan hampir penyebut pada fungsi silinder pada setiap kawasan

Approximate function for unsteady aerodynamic kernel function of aeroelastic lifting surfaces

Prediction of unsteady aerodynamic loads is still the most challenging tasks in flutter aeroelastic analysis. Generally, the numerical estimation of steady and unsteady aerodynamics of thin lifting surface is conducted based on an integral equation relating aerodynamic pressure and normal wash velocity. The present work attempts to increase the accuracy of the prediction by using an approximate approach to evaluate kernel function occurring in the integral equation in the form of cylindrical function. Following previous approximation approaches by other researchers to solve the cylindrical function for planar lifting surfaces, this paper extends such approaches to non planar lifting surfaces. To increase the accuracy of the method, the integration region of the kernel function is divided into two parts – near and far regions, where a nonlinear regression curve fitting technique is adapted to estimate the denominator part of the cylindrical function of each regio

Alternate approximate function for kernel function of oscillating lifting surfaces

Prediction of unsteady aerodynamic loads is still the most challenging task in flutter aeroelastic analysis. Generally the numerical estimation of steady and unsteady aerodynamic of thin lifting surface is conducted based on an integral equation relating aerodynamic pressure and normal wash velocity. The present work attempts to increase the accuracy of the prediction by using an approximate approach to evaluate kernel function occurring in the integral equation. Following previous approximation approach to solve the cylindrical function for planar lifting surface, in the present work such approach is extended to non planar lifting surfaces. To increase the accuracy of the method, the integration region of the kernel function is divided into two parts namely near and far regions, where a nonlinear regression curve fitting technique is adapted to approximate the denominator part of the cylindrical function of each region

An Evidence-Based Review on Shirodhara: A Unique Panchakarma Therapy

Shirodhara is a procedure consisting of continuous pouring of a stream of medicated oil, milk, buttermilk, etc. on the forehead of the patient from a specific height for a specified period. Acharya Vagbhatta has described four types of Murdha Tail i.e., Abhyanga, Parishek, Pichu, and Shirobasti, which is successively more beneficial than the previous one. Shirodhara or Shiroparishechan is one of them. Indication of Shirodhara was found in our ancient textbooks in various diseases like Ardhavabhedaka, Suryavarta, Ardita, Pakshaghata, Hanugraha, Akshishula, Nidranasha, Shirogata Vata and Shirahkampa. In the modern era, it is a very widely used Panchakarma therapy and in this review article, an evidence-based approach is used to define the type, procedure, indication contraindication, mode of action, complications and management and evidence of efficacy etc. of Shirodhara. Based on evidence Shirodhara has been found effective in various disorders like Insomnia, Psoriasis, ADHD in children, Shirah Shoola, essential hypertension, cerebral ischemic stroke and premature ejaculation when accompanied with other treatment modalities. Shirodhara was found effective on subjective as well as scientific parameters or modern biochemical markers parameters in various studies