Browse Topic: Cowlings
The Electroimpact Automatic Fan Cowl Riveter exhibits new and unique design features and automated process capabilities that address and overcome three primary technical challenges. The first challenge is satisfying the customer-driven requirement to access the entire fastening area of the fan cowl doors. This necessitates a unique machine design which is capable of fitting ‘inside’ a fan cowl door radius. The second challenge is determining drill geometry and drill process parameters which can produce consistent and high-quality countersunk holes in varying mixed-metal stack-up combinations consisting of aluminum, titanium, and stainless steel. The third challenge is providing the capability of fully automatic wet installation of hollow-ended titanium rivets. This requires an IML-side countersinking operation, depositing sealant throughout the OML and IML countersinks and the hole, automatically feeding and inserting a rivet which is only 5mm long and 6mm in head diameter and flaring
This SAE Aerospace Information Report (AIR) defines the helicopter bleed air requirements which may be obtained through compressor extraction and is intended as a guide to engine designers
This document summarizes types of heat sinks and considerations in relation to the general requirements of aircraft heat sources, and it provides information to achieve efficient utilization and management of these heat sinks. In this document, a heat sink is defined as a body or substance used for removal of the heat generated by thermodynamic processes. This document provides general data about airborne heat sources, heat sinks, and modes of heat transfer. The document also discusses approaches to control the use of heat sinks and techniques for analysis and verification of heat sink management. The heat sinks are for aircraft operating at subsonic and supersonic speeds
In the modern automobile scenario in developing countries, customers are getting more meticulous and market more competitive. Now even the budget vehicle customer expects desirable vehicle performance in specific use cases of the vehicle that were previously not focused by designers. Hence, the focus on perceived quality challenges automobile engineers to go the extra mile when it comes to the cost-effective design of parts that are tangible to the customer. A vehicle's cowl cover is one such exterior component. The primary functions of this part are to provide air intake opening for the HVAC system and cover the components like wiper motor. The aesthetic function is to cover the gaps between windshield, hood, and fender as seamlessly as possible. A specific role of cowl cover, which calls for a designer's attention, is its load-bearing capability. This component has to be stiff enough to bear external loads like snow accumulation or application of hand on the part by customer or
A tested method of data presentation and use is described herein. The method shown is a useful guide, to be used with care and to be improved with use
A large amount of heat generated in the engineering compartment in a hovering helicopter may lead to premature degradation of inner skin of its engine cowling and cause serious failure on the engine cowling. This study proposes a solution of improving heat resistance of the helicopter engine cowlings by replacing the currently used intumescent coating with a ceramic coating material, Cerakote C-7700Q. Oven and flame tests were designed and conducted to evaluate the heat resistance of Cerakote C-7700Q. The test results show that the currently used painting scheme of the engine cowlings failed the 220°C oven test while after replacing the epoxy seal coat with the Cerakote, the new painting system passed the 220°C test in regards to painting bubbling. Based on that, a new painting scheme with C-7700Q implemented was recommended. It is suggested that the most time- and cost-effective solution to improve thermal performance of the helicopter engine cowlings is to repaint the current engine
The effective cooling of a two wheeler scooter engine depends on the efficient performance of the cooling fans. In scooters, centrifugal fan with axial air inflow and radial outflow with either backward curved or forward curved blades are used. The air flow enters the unit axially and then spreads out turning to 90 degrees into radially outward direction before meeting the engine. The work aims at the study of performance characteristics of the forward and backward curved fans when put in to engine cowling and to compare the power consumed and flow delivered by the fans. The objective is to compare and reduce the power consumed by the cooling fans and to increase the air flow velocity across the engine surfaces. A Conjugate Heat Transfer analysis has been done to study the effect of forward and backward cooling fans on flow delivered, power consumed and engine surface temperature. RANS K-Epsilon two equation turbulence model was used to solve the 3-D numerical model. Moving Reference
To improve the performance and durability of two-stroke engines, temperature of the liner/block is an important parameter, which needs to be optimized. In this paper, an attempt is made to measure and investigate the maximum liner temperature of a forced-air-cooled two-stroke engine. The vehicle was tested on both chassis dynamometer and test track to identify the maximum liner temperature during operating conditions. Thermocouple locations were selected at or near the hot spots (TDC & Exhaust port) in the cylinder block. The chassis dynamometer test revealed that the maximum liner temperatures for the test vehicle were near the exhaust port reference position (34 mm from the top face of cylinder block) and TDC reference position (8 mm from the top face of cylinder block near the exhaust port). The Computational Fluid Dynamics (CFD) simulation was used to study the flow pattern around the block and the results revealed that design modifications can be done on the base cowl to improve
In-flight icing occurs when supercooled water droplets suspended in the atmosphere impinge on cold aircraft surfaces. Thin layers of accreted ice significantly increase aerodynamic drag while thick layers of ice severely alter the aerodynamics of control surfaces and lift. Chunks of ice can break away from the airframe and cowlings and be ingested into engines causing considerable damage. Developing durable surfaces that prevent the nucleation of supercooled water or reduce ice adhesion to a point where airstream shear forces can remove it would allow the design of a more robust, energy efficient deicing/anti-icing system for aircraft and other applications. In this work, a simulations based framework is developed to predict anti-icing performance of various nanocomposite coatings under the in-flight environment. The intrinsic multiscale feature of our model allows a rational design of durable anti-icing coatings targeting different (macroscale) structures in an aircraft body through
The main objective of this work is to investigate, by means of numerical simulations, the performance of the engine nacelle ventilation cooling system of a helicopter under hover and forward flight conditions, and to propose a simplified method of evaluating the performance based on rotor downwash flow by taking the synthetical effect of engine nacelle, exhaust ejector and external flow of a helicopter into account. For the engine nacelle of a helicopter, an integrated model of the nacelle and exhaust ejector was set up including the domain of external flow. The unstructured grid and finite volume method were applied for domains and control equations discreteness, and the standard k-ε model was applied for solving turbulent control equations. Using the business CFD software, the flow field and the temperature field in the nacelle were calculated for single inlet scheme and double inlets scheme, total up to 9 schemes. The performance of the exhaust ejector was computed. And the
This paper talks about using an approach to simulate snow mass falling from roof of cab on the cowl tray of a commercial truck and predicting the durability life of the cowl tray based on this loading. It has always been a challenge for analysts to model the behavior of snow/slurry in dynamic simulations especially where the area of concern is structure and not the fluid. The conventional approach followed in most industries would be either to model snow as soft rubber or to divert from the conventional Lagrangian algorithm for mesh movement towards Eulerian method (or ALE algorithm). Although modeling snow as soft rubber captures the basic physics of the problem, it is not able to correctly simulate the fluid structure interaction behavior and the pressure wave movement inside the snow/slurry when it comes in contact with the structure. This is a big shortcoming as the reverberating motion of pressure wave inside the fluids causes cyclic loading of the structure which raises
Progressive demand being placed on more efficient and quite engines require engine subsystem to be optimized without compromising their performance. Cooling system is one of the important engine sub system to be optimized to achieve better performance with reduced noise levels and with minimum power consumption. In the present paper an effort is made to optimize a fan-driven air-cooling system for a small 4-stroke scooter engine. Complete three-dimensional analysis has been done with commercially available computational fluid dynamics (CFD) codes. Analytical results are validated with the experimental results. A good correlation has been observed between analytical and experimental results. The work is done in two phases. In the first phase, complete flow and heat transfer analysis of the present system has been done. Flow analysis revealed flow blockage, significance of leakage through various parts of the cowling, and separation of the flow inside the vane passages of the fan. In the
This specification covers protective shields for engine and tailpipe openings of aircraft and missiles
This recommended practice specifies requirements in addition to those given in ISO 3046 for testing a high speed reciprocating internal combustion marine propulsion engine or propulsion system for recreational and small commercial craft, for the determination of the rated power (single point) or power curve. This code is not intended as a complete laboratory test manual or for derating engines for site conditions
This recommended practice specifies requirements in addition to those given in ISO 3046 for testing a high speed reciprocating internal combustion marine propulsion engine or propulsion system for recreational and small commercial craft, for the determination of the rated power (single point) or power curve. This code is not intended as a complete laboratory test manual or for derating engines for site conditions
This Aerospace Recommended Practice (ARP) outlines the basic general design considerations for aircraft towbars
This recommended practice specifies requirements in addition to those given in ISO 3046 for testing a high speed reciprocating internal combustion marine propulsion engine or propulsion system for recreational and small commercial craft, for the determination of the rated power (single point) or power curve. This code is not intended as a complete laboratory test manual or for derating engines for site conditions
The concept of the Ducted Propulsor as a quiet propulsive device is relatively new and, because of this, there is a justifiable demand to see evidence that the claims made can be met. Over the last two years, Dowty Rotol have done a considerable amount of test work and have amassed measured data on thrust, noise, efficiency, cowl drag and windmilling drag. The main part of the paper is devoted to presenting these data in order to answer affirmatively and convincingly the aircraft designers' question-will it work? To preface this, the paper reiterates the case for the Ducted Propulsor, the idea of which was introduced some time ago. Briefly, it meets the noise regulations predicted to 1980 and beyond, it is lighter than the equivalent Quiet Propeller and costs less. The performance characteristics are about the same but the propulsor affords the aircraft designer more flexibility. Furthermore, it helps to reduce exhaust pollution. Finally, the paper outlines the current program of work
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