Accident of the DC-10 EC-DEG aircraft at Malaga on September 13, 1982

The present analysis of the abortive takeoff-type accident of a DC-10 at Malaga airport gives attention to the velocity profiles of the aircraft from takeoff to ground impact. A fire followed ground impact. Takeoff was initiated by the crew with only 1295 m of runway left beneath the aircraft. On the basis of the data obtained by this analysis, it is recommended that both pilots and other flight crew members be trained to respond to takeoff failures due to causes other than loss of engine power, such as landing gear collapse

User's guide to STIPPAN: A panel method program for slotted tunnel interference prediction

Guidelines are presented for use of the computer program STIPPAN to simulate the subsonic flow in a slotted wind tunnel test section with a known model disturbance. Input data requirements are defined in detail and other aspects of the program usage are discussed in more general terms. The program is written for use in a CDC CYBER 200 class vector processing system

Studi Numerik Centrifugal Fan Tipe Impeller Backward dengan Variasi Putaran Fan

The primary air fan functions as a primary air producer which is used as air to transport coal powder from the pulverizer to the burner to be burned in the boiler furnace. This study aims to obtain the effect of the rotation variation of fan to  fluid flow characteristics such as the distribution of total pressure, the dynamic pressure, the pressure static contours, velocity distribution, and the fan optimal efficiency. This study was numerical study with simulated a backward impeller type centrifugal fan in a two-dimension model using Fluid Computational software with the multiple reference frame method with the variation of fan rotation. Based on the visualization of the pressure contour and velocity distribution, it could be concluded that there was a volute phenomenon, this was indicated that the greater the volume area in the volute is the greater the total pressure value too. Based on the visualization of the outlet velocity distribution at the position of -0,8531m to -1,01301m, it was found that the velocity is close to the value of 0 m/s2. It showed that the minimum velocity in the area due to the volute tongue radius occurs a flow collision and it impacted the velocity in the area decreased up to V=0. From the simulation results, it was found that the greater the fan rotation value was the greater the efficiency value too. It would be verified by the actual operating data of the centrifugal fan with a minimum rotation range value of 1194 rpm to a maximum of 1468 rp

Aerodynamic design of the contoured wind-tunnel liner for the NASA supercritical, laminar-flow-control, swept-wing experiment

An overview is presented of the entire procedure developed for the aerodynamic design of the contoured wind tunnel liner for the NASA supercritical, laminar flow control (LFC), swept wing experiment. This numerical design procedure is based upon the simple idea of streamlining and incorporates several transonic and boundary layer analysis codes. The liner, presently installed in the Langley 8 Foot Transonic Pressure Tunnel, is about 54 ft long and extends from within the existing contraction cone, through the test section, and into the diffuser. LFC model testing has begun and preliminary results indicate that the liner is performing as intended. The liner design results presented in this paper, however, are examples of the calculated requirements and the hardware implementation of them

Model Predictive Control of the Hybrid Ventilation for Livestock

Abstract—In this paper, design and simulation results of model predictive control (MPC) strategy for livestock hybrid ventilation systems and associated indoor climate through variable valve openings and exhaust fans, are presented. The design is based on thermal comfort parameters for poultry in barns and a dynamic model describing the nonlinear behavior of ventilation and associated climate, by applying a so-called conceptual multi-zone method and the conservation of energy and mass. The simulation results illustrate the high potential of MPC in dealing with nonlinearities, handling constraints and performing off-set free tracking. The purpose of this paper is to apply MPC taking into account of the random disturbances from animals and weather condition to calculate the optimal ventilation rate and air flow distribution and the prediction of indoor horizontal variation of temperature through an optimum energy approach. I

Reconstructive surgery of the orbit

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Versatility of Forehead Flaps as a Reconstructive Tool

INTRODUCTION: Forehead Flaps have been in use since ancient times as has been depicted in the classical paintings of the great Susrutha at work repairing the nose of those unfortunate to have their noses cut off as a punishment. The forehead flaps hold a closer relation to us Indians as we seem not only to be pioneers in utilizing this area for reconstruction but also contribute to the further development of their uses. The bipolar Narayanan flap is a point in case. The forehead flaps have waxed and waned in their popularity at various periods in the long history of plastic surgery. Although it has proved its reliability time and again there seems to be a continued reluctance among the younger generations of plastic surgeons in using this virtual treasure trove of tissue for reconstructive options in the head and neck region due to concerns about the donor area scarring. Probably the easy accessibility to technology and the ever increasing popularity of free flaps with their promise of a single-stage procedure – where the tissue can be sculpted to exactly fit the defect and thereby allowing the patient to return to nearnormal life as early as possible – as compared to the multiple stages generally required when the forehead flap is used, distracts surgeons from these age-old and time-tested options. It is also widely accepted that local tissues give the best colour and texture match to any reconstructed area. This is especially applicable to the face. Thus, currently the central forehead flaps are favoured in the nasal reconstruction. The forehead flaps have lent themselves to such a wide variety of uses that a revisit to their different clinical applications is well justified, if only to serve to bring the spotlight back to the most versatile donor area in the face. AIM OF THE STUDY: This study on the versatility of the forehead flaps as a reconstructive tool was done with following aims. 1) To review the various flaps used from the forehead region in Department of Plastic and Reconstructive Surgery, Government Medical College, Chennai. 2) To study the effectiveness of these flaps in various clinical situations. 3) To report our experiences along with the other uses of forehead flaps reported in the literature. MATERIALS AND METHODS: This study was conducted in the Department of Plastic Surgery, Government General Hospital and Madras Medical College over a period of 32 months September 2005 to April 2008. All cases where a forehead flap was used in the reconstruction of a soft tissue defect in the face – either primarily or secondarily – were included in the study. The flaps were loosely classified as central forehead flaps (paramedian, median, oblique forehead flaps and the glabellar V-Y advancement flap) and laterally based forehead flaps (transverse forehead flap, bilobar Narayanan flap, scalping flap, forehead rotation flap, Fricke flap, etc., ). Forehead flaps were done for a total of 29 patients for various indications. One patient died during post-operative period due to anesthetic complications and was not included in the study. So a total of 28 patients accounting for 28 flaps were enrolled for the study after getting their informed written consent. The proforma for the collection of data was made. All the relevant details of the patient during preoperative, surgical, postoperative and follow up periods were collected and analysed. Indications for forehead flap cover in our study included : 1) Post-excision defects in patients with malignancies. 2) Soft tissue defects in patients acute trauma. 3) Patients presenting with post traumatic soft tissue defects at a later date. 4) Patient presenting with a post-surgical defect. The regions where defects were covered with forehead flaps included : 1) Nose, 2) Cheek, 3) Forehead, 4) Eyelid/Periorbita. The age range of the patients was from 3 - 80 yr (average age – 45.21 yr). The study included 2 children (ages 3 and 4 yr) and 2 senior citizens (ages 73 and 80 yr). The study included 18 male patients and 10 female patients. The defects around the medial canthus, eyelids and nose were favoured with one of the central forehead flaps whereas cheek, lateral canthus and lower face and neck defects were favoured with the transverse forehead flaps. RESULT: A total number of 28 patients were included in the study over a period of 32 months between September 2005 to April 2008. Among the 28 patients who underwent various forehead flaps, 15 patients had primary or delayed primary cover for post-excisional defects. The majority of these were transverse forehead flaps with or without modifications. The majority of the flaps healed well although they invariably were staged procedures. Transverse forehead flaps seem to require a minimum of 3 stages – flap elevation and inset, flap division and flap thinning/commissuroplasty with or without reanimation of the oral sphincter. This is also the group that had maximum post-operative complications (partial/complete flap necrosis). Although an objective assessment was not made regarding the patient satisfaction with the esthetic outcome, most of the patients were not happy with the end result in terms of appearance in the immediate post-op period. On further followup, however, most of the patients seem to be satisfied with the end result. CONCLUSION: The following conclusions can be made from this study: 1. The forehead is a versatile donor area for head and neck reconstruction. 2. The forehead flaps have a robust vascularity and are reliable. 3. Properly planned forehead flaps are adequate and effective for most of the nasal defects and many of the post-excision defects in the face and neck. 4. The uses of the forehead flaps are only limited by the imagination and skill of the surgeon

Вплив геометричних параметрів щитка Крюгера на підіймальну силу крила літального апарата

The front wing mechanization is used in lots of passenger aircrafts. Since it plays an important role during take-offs and landings, aerodynamics has the task of optimizing it. In this paper is examined one of the variants of mechanization of the leading edge of the wing, the Kruger's flap. The Kruger's flap geometric parameters were defined and then changed. They include: the size of the gap between the profile and the flap, the flap adjustment angle and location angle. Investigation of the geometric parameters of the Kruger's flap and their effect on the lifting force of the wing allow us to obtain the optimal geometry of the flap, which will create the largest lifting force among all the variants. The purpose of this master's thesis is to study the influence of the geometric parameters of the Kruger's flap on the lifting force of the wing of the aircraft, namely: -Influence of the adjustment angle of the Kruger's flap on the lifting force and the resistance force of the aircraft; -Influence of the gap between the Kruger's flap and the airplane's profile on the lifting force and the resistance force of the aircraft; -Influence of the Kruger's flap placement on the lifting force and resistance force of the aircraft. The object of the study is the process of airflow over the Kruger's flap. The subjects of the study are the aerodynamic characteristics of the aircraft with the Kruger's flap. The scientific novelty of the results is obtained due to the studies that have not yet been conducted, that allow us to make recommendations for improvement of the aerodynamic characteristics of the aircraft, and save money for aerodynamic performance researches

Study of a pneumatic separator for grain cleaning

This article deals with experimental studies of a pneumatic separator with a passive deck. Post-harvest handling of grain is one of the important operations in grain production. Quality cleaning and drying contribute to grain storage without significant losses. The grain litter after the harvest of the combine harvester, which takes place in the shortest possible time, is the most clogged. This causes a problem in terms of cleaning. An important problem is also the physical and obsolescence of the cleaning machines, even though the annual workload is relatively small. This has a significant impact on productivity. Of all those in the agricultural industry, the most commonly used separation of grain from impurities is by aerodynamic properties and separation by size on the sieve. The design of an experimental pneumatic separator with a passive deck was developed. Experimental studies of the pneumatic separator with a passive deck were carried out, based on which plots of the dependences of the completeness of the separation were plotted on the angle of inclination of the flap and the feed of the grain material. The optimal parameters and modes of the grain cleaning machine were determined: the lowest losses of the main crop and the cleaning efficiency are achieved at the flap inclination angle α=0˚

Finite element analysis based on a parametric model by approximating point clouds

Simplified models are widely applied in finite element computations regarding mechanical and structural problems. However, the simplified model sometimes causes many deviations in the finite element analysis (FEA) of structures, especially in the non-designed structures which have undergone unknowable deformation features. Hence, a novel FEA methodology based on the parametric model by approximating three-dimensional (3D) feature data is proposed to solve this problem in the present manuscript. Many significant anci effective technologies have been developeci to detect 3D feature information accurately, e.g., terrestrial laser scanning (TLS), digital photogrammetry, and radar technology. In this manuscript, the parametric FEA model combines 3D point clouds from TLS and the parametric surface approximation method to generate 3D surfaces and models accurately. TLS is a popular measurement method for reliable 3D point clouds acquisition and monitoring deformations of structures with high accuracy and precision. The B-spline method is applied to approximate the measured point clouds data automatically and generate a parametric description of the structure accurately. The final target is to reduce the effects of the model description and deviations of the FEA. Both static and dynamic computations regarding a composite structure are carried out by comparing the parametric and general simplified models. The comparison of the deformation and equivalent stress of future behaviors are reflected by different models. Results indicate that the parametric model based on the TLS data is superior in the finite element computation. Therefore, it is of great significance to apply the parametric model in the FEA to compute and predict the future behavior of the structures with unknowable deformations in engineering accurately