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The purpose of this paper is to improve the design of a solid square canopy of a parachute. The design improvements are brought out by providing minor slits in the canopy area. Proper designing of the parachute was carried out using theoretical investigation coupled with experimentation. This parachute is designed for launch of sonobuoy from fixed wing aircraft.

Literature review was carried out on the design of such parachutes for the launch of a sonobuoy from a high altitude to the water entry. Computational fluid dynamics (CFD) analysis provided the value of the coefficient of drag for the slit-cut square canopy parachute, with and without sonobuoy for different lengths of the slit. Besides the theoretical investigation, experimentation was also carried out to validate the design.

The experimentation was carried out on 58 and 75 gsm fabric canopies with the slit edge plain-cut with thermally sealed edges, stitched and strengthened. In the case of plain-cut slits on the canopy made of 75 gsm fabric, no tearing of the slit edge was observed in dynamic and flight tests.

The present work has been carried out considering various assumptions and limited trial data specific to precision drop of 9 kg payload. The work can be adopted for bigger parachute for dropping of higher payloads.

Lab strength test, track dynamic and flight trials were conducted to acquire useful data for the present analysis. Besides the theoretical investigations and CFD analysis inherently based on numerous assumptions, experimentation was carried out as the sonobuoy deployment conditions are full of uncertainty. Dynamic and airdrop tests were conducted for this reason to determine design changes in the slits, both at the material level and on improvisations.

The purpose of this review paper is to outline the parachute materials and its behavior. To enhance parachute life, it is highly desirable to consider the commercial angle for any parachute manufacturing industry and its components under varying operational conditions. Hence, the knowledge of various textile materials and operational conditions which contributes the parachute strength and durability will be helpful for industries/researchers.

This section is not applicable for a review paper.

Parachute is a material used in numerous real-time applications such as man-drop, cargo delivery, aircraft recovery and aircraft decelerator which drastically reduces human efforts and time. However, each application requires a unique design and fabric selection to achieve the area of drag needed and the terminal velocity of the parachute material while in flight. For designing a man-drop parachute, the most critical parameters are weight and strength which must be considered during manufacturing. The army person uses the man-drop parachute, which must be as light as possible.

This paper is an original review work and will be helpful for parachute manufacturers/researchers to enhance the life of parachutes with improved functionality.

To explore three‐dimensional scanning technology in capturing the shape of inflated parachutes for accurate estimation of surface area and volume.

The volume and surface area of an inflated round parachute are important parameters for the design and analysis of its performance. However, it is difficult to acquire the three‐dimensional (3D) surface shape of a parachute due to its flexible fabric and dynamic movement. This paper presents how we collect 3D data with a laser scanner and calculate volume and surface area of parachutes from their scans. The necessary data clean and approximation steps with non‐uniform B‐spline function are introduced and implemented. Numerical integration methods are employed to estimate surface area and volume. The approximation of the parachute based on an ellipsoid is compared with the numerical integration approach in their volumes and surface areas.

It is found that 3D scanning technology, with help of mathematic program developed, provides a feasible mean to estimate the surface area and volume of inflated parachutes. The numerical integration method derived in this paper is reliable and robust for the computation.

It is the first time that the 3D shape of an inflated parachute has been scanned with a laser scanner. The mathematical methods developed for processing of scan data are useful for others who use 3D scanning technology. The computational approach and results of surface area and volume of inflated parachutes are valuable to parachute performance modeling and design community.

Parachutes are equipment that is repeatedly used as and when needed. Some of them are used for as many as 60 jumps. The property of the canopy fabric gets deteriorated with use. It is evaluated by destructive tensile and bursting strength. This study aims to focus on the nondestructive evaluation of the canopy fabric's fitness by testing air permeability and relating it with bursting strength. Predictor equations were developed to determine bursting strength from air permeability values.

ANOVA techniques and statistical regression equations were formed.

A series of samples containing five parachutes fabrics was used seven times, and their air permeability and bursting strength were determined to find the extent to the effect of reuse of parachute fabrics on their bursting strength and air permeability determination. It was found that there was a progressive drop in bursting strength and an increase in air permeability. An investigation of the extent of determination in terms of bursting strength and an increase in air permeability following the sense of five different types of parachute fabrics is reported.

The work focuses on the prediction of bursting strength to textile materials only and may not apply to other materials like membranes and sheets. The process of determining air permeability is relatively simpler and faster.

The bursting strength can be predicted for used parachutes, which are otherwise subjected to destructive testing.

The men using the parachutes can be assured of the superior flawless performance of the parachute as equipment and also contribute to the saving of resources due to nondestructive testing, 100% evaluation of all parachutes is possible.

This article describes the nature of the test procedure and discusses the means of introducing it to users of parachutes. It is accepted that the method must undergo field evaluation and possible modification before it can become a routine tool of parachute using organizations.

The purpose of this paper is to describe a set of simple yet effective, numerical method for the design and evaluation of parachute-payload system. The developments include a coupled fluid-structural solver for unsteady simulations of ram-air type parachutes. The main features of the computational tools are described and several numerical examples are provided to illustrate the performance and capabilities of the technique.

For an efficient solution of the aerodynamic problem, an unsteady panel method has been chosen exploiting the fact that large areas of separated flow are not expected under nominal flight conditions of ram-air parachutes. A dynamic explicit finite element solver is used for the structure. This approach yields a robust solution even when highly nonlinear effects due to large displacements and material response are present. The numerical results show considerable accuracy and robustness.

A simple and effective numerical tool for the analysis of parachutes has been developed.

An analysis code has been developed which addresses the needs of ram-air parachute designers. The software delivers reasonably accurate results in a short time using modest hardware. It can therefore assist the design process, which nowadays relies on empirical methods.

TWENTY‐ONE years devoted to the development of ejection seats, 24,000 seats built for more than forty nations and now one thousand lives saved—that is the proud record of the Martin‐Baker Aircraft Company. To coincide with these achievements, the following article describes the technical development of the range of seats—from the first swinging arm concept through the early manually‐operated seat to the rocket‐assisted completely automatic zero/zero ejection seats of today. From whatever standpoint Martin‐Baker's record is examined, the result is impressive. In terms of mechanical engineering, a series of ingenious features allied to robust design have resulted in ejection seats of unparalleled performance yet renowned for their simplicity and reliability. In terms of sales, this comparatively small firm has, in effect, conquered the world and won substantial export contracts—not least those for over 7,000 seats for the United States armed forces. In human terms, the company has won the grateful thanks of all those aircrew members—a long roll of highly‐skilled and dedicated young men whom some might call the cream of manhood—who but for Martin‐Baker ejection seats would have perished. Small wonder that the name Martin‐Baker has become synonymous with successful ejection.

The purpose of this paper is to make available to the parachute industry tools to predict behaviour of certain textile materials. In addition to this, it is desired to reveal and explain the basic requirement criteria for proper textile material selection. The strength of an assembly as a whole is directly dependent on the strengths of the various joints and seams required to assemble the larger structure. Keeping in mind the complex problem of parachute construction, this research seeks to enlighten the industry about the performance of seams in nylon woven canopy fabrics. Five factors have been studied: different types of weave (plain, rip-stop and twill), density (number of stitches per centimetre), different rows of stitches with lapped seams, different types of stitches (lock stitch, chain stitch and zig-zag) and seam direction (warp, weft and bias direction). Two responses have been analysed, the seam breaking force and the seam efficiency (per cent ratio of seam strength to fabric strength). The test results were subjected to an analysis of variance and the seam strength proved to vary significantly not only with the primary parameters, but with the interactions of the primary parameters as well. That is seam strength (and seam efficiency) changes with each primary parameter but it changes in a different manner when other parameters change. Multiple regressions have been used to construct preliminary predictor equations for seam strength and efficiency, and investigations to provide better equations are in progress.

ANOVA techniques and statistical regression equations were formed.

The work has concluded that twill weave 9 with chain stitch has the maximum seam strength, which makes canopies made with 2/1 twill weave and stitched with lapped seam with four rows of chain stitch optimum for heavy supply droppings with a single use parachute(s). It is evident from the results that twill weave with lock stich has the maximum seam efficiency. This makes the canopies stitched with twill fabric, constructed with lapped seams and four rows of stitches ideal for parachutes to be used multiple times. The brake parachutes on aircrafts and parachutes used by sky divers and air combat soldiers can use parachutes whose canopies can be used many times made out of the above mentioned weave and stitch specification.

Original work was conducted from the woven fabrics.

The purpose of this study is to model the dynamic characteristics of an opened supersonic disk-gap-band parachute.

A fluid-structure interaction (FSI) method with body-fitted mesh is used to simulate the supersonic parachute. The compressible flow is modeled using large-eddy simulation (LES). A contact algorithm based on the penalty function with a virtual contact domain is proposed to solve the negative volume problem of the body-fitted mesh. Automatic unstructured mesh generation and automatic mesh moving schemes are used to handle complex deformations of the canopy.

The opened disk-gap-band parachute is simulated using Mach 2.0, and the simulation results fit well with the wind tunnel test data. It is found that the LES model can successfully predict large-scale turbulent vortex in the flow. This study also demonstrates the capability of the present FSI method as a tool to predict shock oscillation and breathing phenomenon of the canopy.

The contact algorithm based on the penalty function with a virtual contact domain is proposed for the first time. This methodology can be used to solve the negative volume problem of the dynamic mesh in the flow field.

A whole new family of expendable low cost supply dropping parachutes have been introduced by the G.Q. Parachute Company Ltd. The new parachute was demonstrated before a large gathering of overseas visitors and services representatives at R.A.F. Old Sarum on November 14, when a whole series of drops with loads ranging from 300 to 2,000 lb. was carried out with remarkable precision in spite of the fresh wind and poor visibility. The new canopies behaved well and it was noteworthy that the initial oscillations after deployment were quickly damped out.

The purpose of this paper is to suggest and research a method for passenger life‐saving in a badly damaged aircraft scenario.

The small parachute, brake rocket and inflatable pillow are used for research and design. Theory of braking is offered, researched, developed and the brake possibilities are computed.

It is shown here that previous works which have proposed using only parachutes are useless because these failed to consider the likely overload of the parachute jerk stress (at the moment of parachute release) and the impact of aircraft on the Earth's surface. These jerks and impacts destroy aircraft and kill passengers.

This method is limited by an additional weight of the brake system.

Offered is a new method for saving passenger lives in any catastrophic situation, including total failure of aircraft control, extreme damage and loss aircraft wings, tail, breakdown all propelling engines, etc.

Offered is a connected series of related technical innovations which overcome obvious difficulties and allow for a soft, near zero speed landing in any topographically suitable place, allowing potential to save aircraft. This method may be applied to all existing airplanes and increases their weight only about 1.5/2.5 per cent. Also, the method may be used for vertically landing the already built aircraft, for example, when any runway is damaged or would become overloaded.