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Institute of Space and Astronautical Science JAXA develops the radio altimeter and velocity meter (landing radar) that is one of mandatory navigation sensor for a planetary lander. The landing radar can measure its relative altitude and speed from planetary surface by C band pulse. The BBM with the function which can measure speed and an altitude simultaneously was manufactured and the field experiment has been done by using helicopter that carried the BBM radar. From the result of field experiment, the BBM radar realized the design performance and attained five percent of the required accuracy from the lander system. This paper introduces the BBM and the algorithm of radar and the accuracy of altitude and velocity measurement by the landing radar BBM., 資料番号: AA0049500074, レポート番号: JAXA-SP-06-006

資料番号: AA0063353024

Institute of Space and Astronautical Science JAXA develops the radio altimeter and velocity meter (landing radar) that is one of mandatory navigation sensor for a planetary lander. The landing radar can measure its relative altitude and speed from planetary surface by C band (4.3 GHz) pulse. The maximum range of this landing radar is 3.5 km. In this paper, we describe functions and parameters of the BBM Radar and the dynamic flight experiment using aircraft., 資料番号: AA0049122039

Collisions of lead-zirconate-titanate (PZT) elements with hypervelocity microparticles are described. Responses immediately after collision are particularly studied to deal with information on velocity and/or mass at impact. The potential of the PZT element is discussed to realize a real time dust detector in space. A small area on ISS (International Space Station) is needed to establish its calibration and further development., 資料番号: AA0048095040

Some trials to detect fine-scale coherent vortices in turbulence are presented in the present paper. The simplest method is a conditional measurement using an X-probe. Various turbulence fields at R(sub lambda) = 19 to 2,300 could be measured by this method and the Reynolds number dependences of the characteristics of the fine-scale coherent vortex were obtained. But, such data showed an error caused by the third velocity component unmeasured. So employed was a double-X probe that can measure three components of instantaneous velocity fluctuation. The resultant data showed that the fine-scale coherent vortex was slightly different, from the Burgers' vortex. Also examined was the array of X-probe that can measure instantaneous 2-D velocity profiles. Though it is in progress of such experiments, the primary results showed the validity of the conditional measurement using single X-probe., 資料番号: AA0047776006, レポート番号: JAXA-SP-04-002

資料番号: AA0047118098

資料番号: AA0045426079

We focus on the dynamic Particle Accumulation Structure (PAS) due to thermocapillary effect in a half-zone liquid bridge. In present study, we analyzed effects of liquid-bridge shape described by its volume ratio upon shape of the PAS itself and motion of particle on the PAS by tracking particles in the liquid bridge and by measuring temperature on the free surface. It is found that the variation of the liquid-bridge volume ratio leads to a significant variation of the temperature gradient on the free surface, which results in difference of the shape of the PAS. By considering the particle motion as simply modeled motion, we explained that the variation of the PAS shape is determined by drastic change of the axial velocity of the particle., 資料番号: AA0063706037

動き検出アルゴリズムとして勾配法とテンプレート・マッチング法に焦点を絞り調査を行なった。ヒトの視覚と同程度の空間解像度(視覚)のビデオカメラと1/500のBoeing 747-200Fの模型を使い、ヒトが約2kmの距離から実物を見た場合に相当する画像をコマ撮り撮影し、動き検出アルゴリズムの評価を行なった。オプティカルフローの明度勾配方向成分が最大値を取る方位をオプティカルフローの方位とするLocal勾配法を提案し、動きに応じて空間フィルターと閾値を調整することにより、1画素程度の誤差で動きを検出し、航空機全体で約15点(視野角0.3度に1点の割合)の密度で動きを検出した。比較の為に、Global勾配法とテンプレート・マッチング法による動き検出を行なった。, The gradient based method was evaluated as to its accuracy and space resolution in motion detection. The velocity was determined as the maximum of the optical flow components in the direction of the brightness gradient from the video image sequences in a miniature world. The standard deviations of measured velocity were 0.4 picture elements (p.e.) at a speed of 1.8 p.e., and 0.8 p.e. at a speed of 7.2 p.e. with four channels of space frequency. The method required about a thousand picture element data to detect one velocity., 資料番号: AA0000595000, レポート番号: NAL TR-1301

The experiments were conducted to measure the velocities of flow around a circurlar cone. Because of variaton of the cross section area in the longitudinal axis, the flow around the the circular cone behaves very high complex and forms the vortex streets which are issued from both side of the cone and attach in downstream to the plate setting it. The flow fields were visualized using the mixed particles in water and resulted in the velocity fields by the method of Particle Imaging Velocimetry (PIV). From analyses of the instantaneous velocity fields, the Strouhal numbers which showed an interesting variation were gained to the Reynolds numbers.

The swirl and axial components of gas velocity in the disk-type combustion chamber of a firing engine were measured by an LDA. The engine was operated under the conditions of a speed of 1500rpm, η_υ=0.5, φ=1.4 and ignition timing of 30°BTDC. The gas velocities at 9 points on a diameter at midheight of the combustion chamber were analyzed by the cycle-resolved method. The bulk (mean) velocity was determined by the frequency discrimination method with the cut-off frequency of 667Hz. The flame propagation pattern was detected by ionization probes set at 17 points on the piston. It has been observed that, in the case of fired operation, the turbulence intensity is higher, the integral length and micro length scales are longer and the swirl flow is weaker and is eccentrically shifted compared with the case of motored operation. These results show that it should be noted that there are remarkable differences in the gas flow between motored operation and fired opeation.

本報告書では低騒音STOL(短距離離着陸)実験機「飛鳥」の3種類のピトー静圧系統の位置誤差を述べる。「飛鳥」の位置誤差は静圧誤差のみより求め、総圧誤差は無視できると仮定した。電波高度計および航空機追跡用レーダによる基準高度の時歴を用い、圧力伝播遅れを補正することによって、速度および高度変化を伴うデータについても位置誤差解析を行った。また、着陸進入中の地面効果が位置誤差に及ぼす影響についても述べる。さらに、慣性速度を基準として高迎角時における位置誤差についても検討した。位置誤差解析結果は他の様々な飛行試験データ解析に使用されたほか、digital air data computerの位置誤差補正式に反映され、較正対気速度および位置誤差補正済み気圧高度がパイロットに表示された。, The position error is reported for three different pitot-static systems used in the National Aerospace Laboratory (NAL) Quiet Short Take-Off and Landing (QSTOL) experimental aircraft 'ASKA' being determined using only the static pressure error, and assuming that the total pressure error is negligible. It was found that a continuous reference altitude and a correction for pressure propagation lag realized determination of the position error during speed and altitude transition. The continuous reference altitude was obtained precisely by the combination of a radar altimeter and an aircraft tracking radar. The ground effect on the position error before touchdown is also reportcd. In addition the position error in high angle of attack cases was discussed. The resultant position error correction was used for various analyses of flight test data. Furthermore, it was incorporated into the Digital Air Data Computer to indicate the calibrated airspeed and altitude to the pilots., 資料番号: AA0004087000, レポート番号: NAL TR-1144

高速飛行実証フェーズ2は宇宙往還機型機体の遷音速空力特性を取得することを主目的とする飛行実験である。この飛行実験では高高度気球を使用して吊り上げた機体を高度19〜31kmの非常に高い高度から滑空させることによって空力特性の取得を行う。しかし、音速近傍では衝撃波の発生に伴う非線形な空力現象のために高い精度のエアデータを取得することは困難である。さらに、この機体は高高度を飛行するため、地上に較べて極めて低い動圧の環境においても信頼性の高いエアデータを取得することが要求される。そこで、この高い要求に応えるために、汎用の5孔ピトー管方式のADSを基に、静圧孔の追加を行ってマッハ数精度を向上させることにより高高度・遷音速においても必要な精度を維持してエアデータを供給できるエアデータセンサー(ADS)の開発に成功した。本稿ではこのADSの開発過程とシステムについて述べる。, The High Speed Flight Demonstration (HSFD) Phase 2 is a flight test program designed to assist in the accumulation of technical expertise for the Japan's re-entry vehicle development. The main objective of the program is to acquire the transonic aerodynamic characteristics of re-entry type vehicles. The flight test vehicle was strung up to an altitude of 19 - 31 km using a stratospheric balloon and made a free flight after release. During the free flight, the aerodynamic characteristics were measured. Although the air data such as Mach number, angle of attack or sideslip angle are vital to analyze the aerodynamic data, it is difficult to acquire accurate air data in the transonic region because of the non-linearity due to the shock wave. In addition, because the flight tests were performed at a very high altitude, the dynamic pressure was very low and that made the air data acquisition more difficult. To achieve those severe requirements, an air data sensor (ADS) based on the principle of non-nulling 5-hole probe, which was originally developed for conventional airplanes, was adopted. Because the original probe could not achieve the requirements due to the severe flight conditions of the HSFD Phase 2, the precision augmentation was made by additional static pressure holes on the stem surface of the probe and succeeded to provide accurate air data. In this document, the development process and the system of the ADS of the HSFD Phase 2 are described., 資料番号: AA0048457000, レポート番号: JAXA-RR-04-043

垂直離着陸型ロケットが降下時にエンジンを再着火して減速・軟着陸する場合、一様流とエンジンの逆噴射流との千渉が、空力特性に大きな影響を与える。これまでに行われた風洞試験による力計測では、計測された機体抗力係数C(sub d)は、逆噴射時、推力の増加に伴い抗力は増加するものの、ある推力範囲においては、ジェット噴射なし(推力0％)よりも、抵抗値が小さくなる場合があり、条件によっては、逆噴射によって降下速度が増す可能性があることが指摘されている。これらの現象については、逆噴射ジェットと一様流との干渉によって生じる流れ場が、推力の違いによって大きく変化することが予想されるが、その詳細については、未だ明らかとはなっていない。逆噴射ジェットの空間速度場計測に対して、PIV(Particle Image Velocimetry)を用いることで、従来のプローブを用いた点計測とは異なり、瞬時の空間速度場情報を得ることが可能なため、非定常性が強い速度場における高い有効性が期待される。そこで本研究では、この干渉流の空力特性に影響を与えるメカニズムを解明する目的で、PIVシステムによる空間速度分布の計測を試みた。その結果、逆噴射ジェットの形状やよどみ点位置に関する情報を得るとともに、平均および瞬時速度分布並びに乱流強度に関するデータを取得した。これらの計測結果より、逆噴射ジェットと一様流との干渉による強い非定常性が観測され、さらに、ジェットの有無により、ノズル出口上流部の流れの変化だけでなく、模型後流部での剥離の状態が大きく変化することが明らかとなった。以上の結果より、PIV計測により、逆噴射時の場合、噴射なしの場合より抵抗が小さくなるという現象が生じる原因に関して、流れ場との対応関係が解明された。, For a vertical-landing rocket, one of the most important issues is the reliability of vertical soft landing using the opposing jet of the rocket engine. The interaction between engine plumes and the free stream becomes important in the design of an attitude control system in the powered deceleration phase of landing. Since this interacting region has highly nonlinear characteristics, extremely unsteady motion is observed. Measurements for this study were performed in the JAXA 2 x 2 m low-speed wind tunnel using PIV (Particle Image Velocimetry), which improves our imagery and understanding of the complicated flow behavior. From the PIV measurements we obtained two component velocity fields of the opposing jet flow in a vertical model rocket landing, and derived the shape of the opposing jet, stagnation point, and intensity of turbulence. It was also found that the aspect of flow separation in the wake region was changed by the opposing jet., 資料番号: AA0049188000, レポート番号: JAXA-RR-04-041

一酸化炭素などの温室効果ガスによる地球環境への影響が国際的な問題になっている。航空宇宙技術研究所では国立環境研究所と共同で温室効果ガスの発生・吸収に関するメカニズムを解明するために航空機を使って観測を行っている。地上の植生などによる温室効果ガスの発生・吸収(フラックス)を広い範囲にわたって詳細に観測する際には航空機が有利である。そのためにガス濃度の測定と同時に正確な風速ベクトル計測によりフラックスと風と関係を明らかにすることが不可欠である。ここでは気象観測などに用いられてきた高精度の超音波風速計を航空機用風速計として改良・開発した。風洞試験および実験用航空機(B-65)での飛行試験によりその特性を明らかにし改良を重ねてきた。また、実験用航空機ドルニエ機(Do-228)で釧路上空で又、クインエアー機(B-65)で苫小牧上空を飛行してフラックスの測定を試みた。風を測るためにドルニエ機(Do-228)で多角錐型ピトー管を使用し、クインエアー機(B-65)では超音波風速計を使用した。航空機に搭載した非分散赤外検出器によりCO2濃度の逐次変化データを計測し、超音波風速計から3次元風速を計測し上下風を算出した。この連続に計測したCO2濃度と上下風からフラックス測定を行う手法を試みた。, To investigate the pollutant gas mass transport in the atmosphere, it is necessary to measure the gas concentration as well as its velocity at once. The ultrasonic anemometer was developed for measuring the three dimensional velocity vectors of air on an airplane. The ultrasonic anemometer has been used often for meteorological wind velocity measurement, but the present study proved it to be a useful instrument for the measurement on board as well up to the velocity range 96 m/s maximum. The application for use on an airplane was demonstrated here to give the air data for three-dimensional velocity components in the atmosphere. The simultaneous measurement of the gas velocity and concentration was demonstrated here by NAL plane, B-65, on board. The data processed resulted in the negative fluxes of the CO2 distribution above the plain investigated, which showed an indication of CO2 absorption by the plants on the ground., 資料番号: AA0046111000, レポート番号: NAL TR-1444

航空宇宙技術研究所 24-25 Sep. 1991 (9th). 16-18 Mar. 1992 (10th) 東京 日本, National Aerospace Laboratory 24-25 Sep. 1991 (9th). 16-18 Mar. 1992 (10th) Tokyo Japan, 1m/s以下の速度領域のための風速計に用いる走行台車システムを述べた。較正しようとする風速計を台車に取り付け、静止空気中で長さ45mのレール上を0.05〜1m/sの範囲の一定速度で走らせる。台車の速度に対して風速計の出力を較正する。, A towing carriage system for anemometers in the range below one m/sec is described. Anemometers under calibration are set on the carriage which moves on the 45 meters long rails through stationary air at a constant speed between 0.05 and one m/sec. The output of the anemometers are calibrated against the carriage velocity., 資料番号: AA0004167008, レポート番号: NAL SP-18

The intensity and structure of turbulence in a flame front may be changed by expansion flow due to combustion. Therefore the velocity and turbulence in a combustion chamber of a spark ignition engine are measured by mans of a laser Doppler anemometer with fiber-optic pick-up under firing conditions. The engine is operated at a speed of 2500 rpm with propane-air mixtures. Data acquisition window width affects the turbulence intensity (u') and integral time scale of turbulence (Lt) of the analysis. In the experiment, a short (0.67 ms) and long (4 ms) window are selected and compared with each other. In the combustion period, twice the intensity of u' and an increase of 40 % in Lt are observed in the case of short window analysis. A stronger u' and larger Lt are observed in the long window analysis and it is shown that the Lt expands laterally during the compression stroke and vertically during the expansion stroke.

The velocity and turbulence in two-dimensional wedge type engine combustion chambers are measured by a laser Doppler anemometer (LDA) with an optical fiber transmitting system under motored and firing conditions. The engine is operated at a speed of 2 500 rpm with propane-air mixtures changing the combustion chamber setting direction to the cylinder, here named normal ""N"" and reverse ""R"" combustion chambers. The preliminary experiment indicates that the flame propagating velocity near the slant ceiling and the indicated mean effective pressure are of a higher level at the R chamber than at the N chamber. The mean velocity U^^-, fluctuation intensity u' and integral time scale of turbulent L_t in both chambers are derived through the stationary time averaged analysis of the measured velocities, and each is compared between both chambers. The results have showed that the flow patterns in both chambers are different and the mean value of the U^^- of the R chamber at the spark timing is large than the other by about 70%. However there is little difference at u' and L_t in both chambers.

The experiments were conducted to measure the velocities of flow around a circurlar cone. Because of variaton of the cross section area in the longitudinal axis, the flow around the the circular cone behaves very high complex and forms the vortex streets which are issued from both side of the cone and attach in downstream to the plate setting it. The flow fields were visualized using the mixed particles in water and resulted in the velocity fields by the method of Particle Imaging Velocimetry (PIV). From analyses of the instantaneous velocity fields, the Strouhal numbers which showed an interesting variation were gained to the Reynolds numbers., 紀要論文

Doctor of Philosophy in Engineering, Doshisha University