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SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, The system of JAXA small supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1) has been briefly explained. Some design problems that the designers have encountered have also been briefly explained., 資料番号: AA0063609067, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, This paper describes the outline of the CFD (Computational Fluid Dynamics) analysis workshop on the NEXST-1 (National EXperimental Supersonic Transport-1) flight test, which was held on October 13, 2006. The NEXST-1 flight test was conducted to validate JAXA's CFD-based aerodynamic design concepts on a future supersonic transport aircraft. The comparison of the flight test data and CFD analysis results validated the design concepts qualitatively, but some quantitative differences were also found. To understand the true effects of the design concepts, those differences should be investigated in detail. As one of the best ways for such investigation, present CFD analysis workshop was planned and the validation of JAXA's CFD results was selected as a main theme. In this paper, first of all, several discussion points to be investigated were summarized. Then, analysis subjects are also described. Four parties finally participated in this workshop and compared their original CFD results with the flight test data to investigate the discussion points., 資料番号: AA0063609066, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, In this study, flow computations were performed on the NEXST-1 (National EXperiment Supersonic Transport-1) with unstructured mesh solver. Two different meshes and two different turbulence models were used. The computational results were compared with NEXST-1's flight data. As a whole, the computational result showed a good agreement with flight data, except the pressure distribution on the lower surface in alpha-sweep cases., 資料番号: AA0063609074, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, Flight test of a supersonic experimental airplane was performed by Japan Aerospace Exploration Agency to improve advanced aerodynamic design technologies for the next generation SST (SuperSonic Transport). The experimental airplane was designed to reduce the drag on a supersonic cruise condition. Surface pressure distributions, boundary layer transition locations and aerodynamic forces in the flight test were obtained to demonstrate the aerodynamic design concepts. The flight test results evaluated by comparing with the prediction results obtained by CFD (Computational Fluid Dynamics) based optimum design tools. The flight test results relatively corresponded to the CFD results. Aerodynamic design concepts for drag reduction were demonstrated qualitatively and quantitatively by the NEXST-1 (National EXperimental Supersonic Transport-1) flight test., 資料番号: AA0063609065, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, Four parties participated in the 4th SST (SuperSonic Transport)-CFD (Computational Fluid Dynamics) Workshop. They analyzed aerodynamic characteristics of the NEXST-1 (National EXperimental Supersonic Transport-1) flight test according to their own CFD analysis plans. After the presentations by four parties, several viewpoints on the future studies were discussed at the workshop. This paper summarizes those discussion points, action items to be studied and JAXA's results on some of the action items after this workshop. As a conclusion, this workshop revealed present JAXA's CFD results were almost valid by comparing them with the flight test data, although some quantitative differences have still remained. Therefore, principal discussion points were focused on turbulence model, transition condition and effect of small parts in the comparison of drag polar curve between the flight test data and CFD results. As concerned with inviscid force characteristics, all CFD results showed a very good agreement., 資料番号: AA0063609076, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, 資料番号: AA0063609071, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, This paper provides CFD (Computational Fluid Dynamics) flow analysis results of the JAXA NEXST-1 (National EXperimental Supersonic Transport-1) for the 4th JAXA SST (SuperSonic Transport) CFD workshop. A hybrid unstructured grid system was employed for viscous aerodynamic analysis. Computations were conducted for the flight test condition, then computed and measured results are compared. Effects of some computational conditions, such as, choice of turbulence modeling, mesh density and numerical scheme, are studied., 資料番号: AA0063609075, レポート番号: JAXA-SP-06-029E

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, A flight test of a supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1) was conducted successfully by JAXA in October 2005. In this study some aerodynamics design concepts were verified by comparing the flight test results with CFD (Computational Fluid Dynamics) analysis using JAXA's CFD codes, a structured mesh code UPACS (Unified Platform for Aerospace Computation Simulation) and an unstructured mesh code TAS (Tohoku university Aerodynamic Simulation). After the CFD codes was verified using a wind tunnel test results, the CFD results were compared with the flight test results. The aeroelastic deformation and the boundary layer transition data of flight test were taken into account to improve CFD analysis. The effect of the design concept of the NEXST-1 was also confirmed by CFD analysis., 資料番号: AA0063609072, レポート番号: JAXA-SP-06-029E

This paper presents continuous efforts of EFC/CFD validation for supersonic flows around NEXST-1. Among them, two topics will be mainly described here. One is an analysis on the measured geometry of the wind tunnel model, showing that discrepancies of pressure distributions are due to the discrepancy of the model geometry. This is remarkable at the outer region of the wing. The other is a simulation with transition. The transition model which was used in previous works cannot occur the transition exactly where it is wanted. Another model used in this work can improve the problem. The analysis with the transition model decreases the discrepancy between CFD results and EFD data., 資料番号: AA0047427043, レポート番号: JAXA-SP-03-002

Development of a next-generation airplane cruising near sonic speed received considerable attention in 2002. It requires a better understanding of corresponding aerodynamic characteristics and CFD validity. As a part of the collaboration between NAL and MHI on transonic wind tunnel tests and CFD computations using NEXST-1 supersonic transport model, the effect of wall interference in NAL 2 m x 2 m transonic wind tunnel at near sonic speed condition was investigated with CFD based on Reynolds-averaged Navier-Stokes equations. The results showed considerable drag reduction (dip) at Mach number just below the drag divergence Mach number due to the interaction of wall and sting support., 資料番号: AA0047427042, レポート番号: JAXA-SP-03-002

Inverse method is applied to geometry estimation of wind tunnel models. By defining the pressure distribution obtained from wind tunnel test as the target of inverse method, approximate geometry estimation is possible. The inverse method used in this paper is based on Takanashi's concept that utilizes integral equations and residual-correction technique. Geometry of two wind tunnel models were estimated. One is 23.5 percent scale and the other is 8.5 percent scale of NEXST-1 (National Experiment Supersonic Transport). The deviation of the estimated value from the original CATIA geometry was within a reasonable order if manufacturing limitation is considered. The geometry of the 8.5 percent scale wind tunnel model was measured for validation by using a non-contact three-dimensional measuring device employing laser beam and auto-focus system. The result shows the validity of the present method for approximate geometry estimation., 資料番号: AA0045948016, レポート番号: NAL SP-57

In the third SST-CFD Workshop held on December 3-5, 2001, the competition of a flow analysis of the NAL NEXT-1 has been conducted and discussed about the comparison of CFD and Wind Tunnel Test results presented by participants. In this discussion, common discrepancies between EFD and CFD were pointed out and NAL accepted to make farther studies to evaluate these discrepancies including WTT using modified NAL 1 m x 1 m Supersonic Wind Tunnel. This report describes the plan of this evaluation work and WTT results of force test and oil flow test., 資料番号: AA0045948017, レポート番号: NAL SP-57

Using the prediction system of boundary-layer transition, the spatial growth of traveling waves is examined in the boundary layer over the outer wing of the NEXST-1 semispan model. It is found from the computational results that TS waves are dominant to transition on the wing. Moreover, it is noted that TS waves directed to the leading edge are amplified even in the accelerated boundary-layer flow near the leading edge. However, the growth of TS waves is suppressed around the designed angle of attack., 資料番号: AA0045948035, レポート番号: NAL SP-57

宇宙航空研究開発機構(JAXA)では小型超音速ロケット実験機(NEXST-1: National EXperimental Supersonic Transport-1)の抵抗低減空力設計コンセプトや最適空力設計ツールの妥当性を検証するため飛行実験を行った。この飛行実験では空力設計の妥当性検証に必要な多くの空力データを取得している。この空力データは大きく、機体周りの表面静圧分布、全機空気力、そして、主翼上面や前胴部の境界層遷移位置計測の3つに分けられ、本稿では表面静圧計測システムについてまとめる。飛行実験では高い信頼性、健全性をもつ計測システムを構築することが必要である。そのため、飛行実験において検証に必要な計測精度を明確にした上で、いくつかの工夫により必要計測精度を満たす圧力計測システムを構築した。さらに、飛行実験前まで徹底したシステムの健全性管理を行い、また、飛行実験後には再度計測システムの精度検証試験を行った。これにより高精度の飛行実験データを取得することができた。飛行実験で取得された表面静圧データを評価し、空力設計の妥当性を検証することができた。, A flight test of a supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1) was performed by Japan Aerospace Exploration Agency (JAXA) to demonstrate advanced aerodynamic design technologies for the next generation SuperSonic Transport (SST). Main issue of the aerodynamic design of the NEXST-1 is the drag reduction on the supersonic cruise conditions. Therefore, four aerodynamic design concepts were applied to the design of the NEXST-1. In the flight test, three kinds of aerodynamic data were obtained to validate the aerodynamic design concepts and design tools. The static surface pressure measurement systems, that is the one of the measurement items on the flight test were described in this report. Wind tunnel tests and functional tests were conducted to improve the accuracy of the measurement systems. Then, high quality pressure measurement system can be constructed on the NEXST-1. System checks were performed to maintain the high reliability before and after the flight test. Measured data from the flight test were also analyzed to confirm the measurement system reliability. From those results, high quality surface static pressure can be measured on the NEXST-1 flight test., 資料番号: AA0064091000, レポート番号: JAXA-RM-08-001

小型超音速実験機は、2005年10月10日に豪州ウーメラ実験場からロケットにより打ち上げられ、超音速で滑空実験後、回収予定地点まで滑空し、パラシュートにて水平降下、エアバッグにて軟着陸し、データレコーダを含む実験機が無事回収された。実験機には離着陸機能がないため、着陸フェーズではパラシュート・エアバッグによる水平姿勢軟着陸方式が採用されている。回収シーケンス中のコンテナの分離、パラシュートのリーフィング解除、パラシュートの分離やエアバッグ用ガスの発生の機構部には火工品が用いられている。使用された火工品は、6種類33個に及ぶ。これ程多くの火工品を搭載した回収システムは、過去にあまり例がない。本稿では、回収システムのシーケンス概要を述べると共にそれぞれのシーケンスで使われている火工品の基本性能、開発試験結果などをまとめる。, NEXST-1 (National EXperimental Supersonic Transport-1) airplane was successfully launched and recovered on October 10th in Australia Woomera test range. Its recovery system utilizes many kinds of pyrotechnics in order to eject parachutes, cut reefing lines, disconnect the parachutes, change the airplane from vertical to horizontal position and open the gas bottle valves of airbags. The number of these pyrotechnics amounts to 33. This paper summarizes the performance of each pyrotechnics of the recovery system and discusses some development test data., 資料番号: AA0063792000, レポート番号: JAXA-RM-07-006

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, CFD (Computational Fluid Dynamics) analyses of a flow field around supersonic transport, NEXST-1 (National EXperimental Supersonic Transport-1) are conducted. The CFD results are compared with flight test data. In this paper, C(sub D) and C(sub p) discrepancies between them are mainly discussed with consideration of the effects of transition and local geometry change by protuberances of measuring instruments. As for the C(sub D) discrepancies, CFD results have more (4-9 cts) profile drag, which could be the sum of spurious numerical error and turbulence model mismatch. As for the C(sub p) discrepancies, C(sub p) values at local points are definitely influenced by protuberances. Through the discussion, we also demonstrate how the CFD simulation can augment the validity of the flight test data., 資料番号: AA0063609073, レポート番号: JAXA-SP-06-029E

小型超音速実験機NEXST-1(National EXperimental Supersonic Transport-1)(以下、ロケット実験機)の第2回飛行実験は、2005年10月10日早朝、南オーストラリア州ウーメラの実験場で実施され、CFD(Computational Fluid Dynamics)検証データ取得を始め全てのミッションを達成して飛行実験は成功した。ロケット実験機の通信系統は、機上と地上を1対の通信系として、飛行データ伝送系のテレメータ装置、非常指令系のコマンド装置、飛行追跡系のレーダ・トランスポンダ装置の3つの通信系で構成されている。本研究開発報告書においては、第2回飛行実験における各通信系の改良設計およびシステム改修について、飛行実験前にオーストラリアARA(Airborne Research Australia)社の小型飛行機を用いて実施した各通信系装置の機能確認飛行試験の結果について述べ、最後にロケット実験機の飛行15分22秒間で得られた各通信系受信信号強度指示値(RSSI: Receiving Signal Strength Indication)と回線設計値の解析・比較を行い、通信系統設計の妥当性ならびにIMU(Inertial Measurement Unit)と追跡レーダの測位を比較した結果について報告する。実験機は背面状態でロケットブースタにより打ち上げられる。本回線設計の検証評価ではロケット噴煙損失モデルの妥当性についても触れた。, The second flight trial of NEXST-1 (National EXperimental Supersonic Transport-1) non-powered and unmanned scaled supersonic experimental airplane has succeeded to acquire the data for CFD (Computational Fluid Dynamics) validations in a perfect mission on October 10, 2005 in the early morning at WPA (Woomera Prohibited Area) in South Australia. The radio communication systems for the trial consist of three kinds system of the telemeter, command and radar-transponder including ground and onboard equipment. This paper describes the results of re-designing and modifying the systems for NEXST-1 second flight trial, and explains the system function test results of the preparatory flight tests using a small test aircraft Dimona of ARA (Airborne Research Australia) equipped with GPS (Global Positioning System) system. Lastly, the paper describes the comparison and validation results of the RF (Radio Frequency) link designed with the flight data RSSI (Receiving Signal Strength Indication) for the 15 minutes and 22 seconds, as well as the positioning comparison between IMU (Inertial Measurement Unit) and Radars. The airplane inversion was launched using the rocket booster. The analysis results of RF link include the exhaust plumes effect for the verification in the flight trial., 資料番号: AA0063919000, レポート番号: JAXA-RR-06-044

宇宙航空研究開発機構・航空プログラムグループが研究を進めている超音速機技術の飛行実証として、2005年10月に南オーストラリア州ウーメラ実験場において小型超音速実験機(NEXST-1: National EXperimental Supersonic Transport-1)の第2回飛行実験を実施した。小型超音速実験機プロジェクトの主要な目的は、次世代SST(SuperSonic Transport)開発を睨んだ最適空力設計技術の開発とその飛行実験による実証である。2002年7月に実施した第1回飛行実験の失敗を受け、改修設計・製造および各種地上試験を行った上、第2回飛行実験に臨んだ。本報告書では、第1回飛行実験以降の小型超音速実験機システムの改修設計・開発および改修設計の妥当性検証内容を概説すると共に、第2回飛行実験の結果について飛行実証項目を中心に報告する。, The flight trial of the unmanned experimental airplane was conducted by Japan Aerospace Exploration Agency (JAXA) in order to substantiate supersonic drag reduction technology with a CFD (Computational Fluid Dynamics)-based optimum aerodynamic design procedure and to establish the experimental system with the non-powered and unmanned supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1). The airplane configuration was designed using the inverse method giving the preferable pressure distribution to minimize the aerodynamic drag force at Mach Number two. On October 10, 2005, the second trial of the NEXST-1 was conducted in Woomera test range of South Australia. Every system had accomplished each work successfully and the NEXST-1 including a data recorder was recovered safely. This report shows the modification of the experimental airplane system after the first trial and the results of the second trial., 資料番号: AA0063991000, レポート番号: JAXA-RR-06-049

小型超音速ロケット実験機(NEXST-1: National EXperimental Supersonic Transport-1)の第2回目の飛行実験を2005年10月に豪州ウーメラ実験場において行った。飛行実験では予定していた全てのシーケンスを正常に実施し、貴重な飛行実験データを健全に取得することができた。その中で、空力データは空力設計コンセプトを検証する上で重要な計測項目のひとつである。本稿では飛行実験で得られた空力データを評価し、空力設計の妥当性について検討した結果を報告する。具体的には、飛行実験により計測された空力データをCFD(Computational Fluid Dynamics)解析結果と比較し、抵抗低減コンセプトを取り込んだNEXST-1の空力設計に対する妥当性を検証することができた。これは機体まわりの表面静圧分布がCFD解析と概ね一致していること、胴体や主翼まわりの表面静圧分布の分析からワープ主翼、エーリアルール胴体の設計コンセプトの妥当性が確認できたこと、さらに主翼上面の圧力分布に関して自然層流翼設計に用いた目標静圧分布と良好な一致が得られたことによる。また気流乱れの小さい飛行実験条件下で、主翼上面や前胴まわりの境界層遷移データの取得に成功し、その遷移計測結果から設計点において主翼上面の境界層遷移位置がもっとも後退していることが明らかになり、自然層流翼設計の妥当性が完全に確認された。さらにその遷移計測結果を数値予測結果と定量的に比較し、境界層遷移予測ツールの精度向上に役立つ知見も得られた。特に設計点における抵抗係数の特性は、飛行実験結果とCFD解析結果で良好な一致が示され、これにより超音速巡航時の設計点における抵抗低減コンセプトの妥当性が定量的に検証された。しかしながら、表面静圧分布や空気力特性の1部の飛行実験データにはまだCFD解析結果や風洞試験結果との不一致が見られ、現在もその原因については検討を続けている段階にある。最後に今回の飛行実験により得られた技術を適用して想定実機スケールのSST(SuperSonic Transport)形状の設計を行い、実機スケールにおいて巡航マッハ数と設計揚力で13％の揚抗比改善効果の得られることを確認した。, Flight test of a supersonic experimental airplane was performed by Japan Aerospace Exploration Agency to improve advanced aerodynamic design technologies for the next generation SST (SuperSonic Transport). The experimental airplane was designed to reduce the drag on a supersonic cruise condition. Surface pressure distributions, boundary layer transition locations and aerodynamic forces in the flight test were obtained to validate the aerodynamic design concepts. The flight test results were evaluated by comparing with the prediction results obtained by CFD (Computational Fluid Dynamics) based optimum design tools. The flight test results were confirmed to be corresponding to the CFD results. Therefore, the aerodynamic design concepts for drag reduction were demonstrated qualitatively and quantitatively by the NEXST-1 (National EXperimental Supersonic Transport-1) flight test., 資料番号: AA0063727000, レポート番号: JAXA-RR-06-041

独立行政法人航空宇宙技術研究所により豪州ウーメラで実施された小型超音速実験機の第1回飛行実験では、主に実験機装備品の制限と飛行安全上の要求により、射点付近の地表面から計測空域の成層圏に至るまで気象の制限が設けられた。また、実験後の飛行データ解析においても計測空域の成層圏の気象データが必要とされた。このため、実験実施可否判断および飛行データ解析に必要な気象データを提供することを目的として、ウーメラ現地での気象観測体制を整備した。射点に気象観測装置、実験機回収点に風向・風速計を設置して地表面付近の気象観測を行なうとともに、バルーンのレーダ・トラッキング、GPSゾンデおよびVHFレーダにより射点上空および計測空域の気象観測を行なった。また豪州気象庁から各種の気象情報・予報の提供を受けた。気象観測体制は実験に先立ち整備・運用され、観測装置の評価を行なうとともに現地の気象データを蓄積した。特にまだ研究的要素が強いVHFレーダに関しては別途飛行試験を実施しその性能を評価した。これらの観測体制により、飛行実験時には全ての気象の制限が満たされていることを確認した上で実験が実施された。さらに現地の気象データの解析・評価を通じて次回の飛行実験に有益な幾つかの知見が得られた。, The first flight trial of the non-powered supersonic experimental airplane (NEXST-1) was conducted by the National Aerospace Laboratory of Japan (NAL) on July 14, 2002 at Woomera, Australia. To acquire weather data for the Go/No-Go decision for the flight trial and for the post-flight analysis, a weather monitoring system was constructed at Woomera by NAL. The automatic weather station and the ultrasonic wind sensor were installed at the launch site and at the retrieval point, respectively. A radar tracking balloon and VHF radar were used to acquire wind data for a height of up to 20 km, where the NEXST-1 experiment was to be performed. Since VHF radar has not been firmly established as a wind monitoring method, another flight test was conducted to confirm its performance. In addition to the NAL weather observations, the Bureau of Meteorology of Australia provided NAL with various weather information including weather forecasts and GPS sonde data released from the Woomera observation site. Using this weather monitoring system, the NEXST-1 flight trial was conducted once all weather criteria had been fully satisfied. Useful information for the next flight trial was also extracted from the analysis of the observed weather data., 資料番号: AA0047389000, レポート番号: NAL TR-1469