An aircraft's survivability in a hostile environment is a mixture of factors that stem from both susceptibility and vulnerability. Conducting analyses that incorporate these factors into a blended solution is vital. One such analysis was conducted using the government-provided Air-Defense Artillery (ADA) simulation tool Radar Directed Gun System (RADGUNS). RADGUNS provides a three-dimensional engagement space to conduct one versus one encounters against Radio Frequency (RF) guided threats. Complex user-generated flight paths can be simulated with varying relative starting locations of the aircraft relative to the threat being considered. The simulations conducted incorporated various aircraft parameters. Aircraft velocity, acceleration rates, deceleration rates, vulnerable area, and radar cross section (RCS) were the primary parameters whose effects were investigated. For each encounter, the Probability of Hit (PH) and Probability of Kill given a Hit (PK|H) were calculated, accounting for the susceptibility and vulnerability segments of the kill chain, respectively. A holistic metric of the kill chain, Probability of Kill (PK), and Engagement Time were the primary results of each engagement. Varying prominent aircraft input parameters can provide key insights in the prediction of an aircraft's survivability. This paper will focus on the benefits of speed and maneuverability, obtainable with Sikorsky's X2 TechnologyTM, in the realm of survivability versus radar and human guided threats.
The US Marines CH-53K King Stallion replaces the venerable CH-53E Super Stallion and delivers almost triple the payload over the primary mission radius of 110 nm, while maintaining the same shipboard footprint. In order to achieve this the main gearbox design had to achieve an unprecedented power density. The main gearbox is a split torque gear box with three input clusters and four dual herringbone drive pinions per cluster. This paper addresses the challenges related to contact pattern development of the MGB 3rd-stage gear meshes.
A high-fidelity engineering simulation model has been developed in FLIGHTLAB for a Sikorsky production helicopter to support future design modifications. The simulation model consists of major subsystems for main rotor, tail rotor, fuselage, empennage, landing gear, flight control system, and propulsion system. As the manufacturer, Sikorsky was able to provide a complete and validated set of model data and a large database of flight test records to ensure the model quality and fidelity. Although the model correlation with test data is satisfactory in most flight conditions including hover, low-speed flight, level flight, and vertical climb, some model-data discrepancies were seen in the forward climb/descent and autorotation test cases. An additional study was conducted at Sikorsky to investigate these discrepancies. Based on the study, a set of model enhancements were developed to improve the model correlation with test data in forward climb/descent and autorotation. These enhancements allow for adjustment of certain semi-empirical corrections to address model limitations at these challenging conditions such as fuselage characteristics and interference at high angles of attack and rotor inflow and interference at low collective settings and near 90-degree wake skew. These enhancements were carefully designed such that the effects were localized so that the model-data correlation was not adversely impacted in other flight conditions. The model-data correlation in forward climb/descent and autorotation were significantly improved by implementing these model enhancements with little to no impact on the other flight conditions resulting in a high-fidelity engineering simulation model validated in the entire flight envelope.
This paper focuses on rotor blade loads analysis and correlation for coaxial rotor applications. Predicted rotor blade loads from two methodologies used in-house at Sikorsky Aircraft were compared with flight test data from a coaxial rotorcraft. The flight conditions for the correlation range from low speed transition flight to high speed cruise flight and a pull-up maneuver. The methodologies being correlated include both a high-fidelity CFD/CSD (Computational Fluid Dynamics coupled with Computational Structural Dynamics) methodology and the Sikorsky-proprietary flight dynamics simulation tool, GENHEL. Detailed blade load correlations were presented at multiple representative flight conditions. In addition, a survey of the prediction accuracies from these tools were carried out to quantify the overall prediction accuracy using critical metrics for both blade structure load sizing and rotor vibrations to support practical design application.
Sikorsky has developed a specification outlining the use of three casting technologies: simulation, additive manufacturing of the mold and low pressure casting. This specification has been used in the past on new development projects with positive results, reducing lead times and number of pours to produce a useable part. When the S-92 program needed to develop a second source for a casting, they worked with Magellan Aerospace to implement the specification. The project proceeded on time with all castings able to be used. Some elements of the specification were modified to work with a legacy part design, including the use of statistical process controls to reduce variability in crucible pouring.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.