How to improve open rotor aerodynamics at cruise and take-off

AbstractA key challenge in open rotor design is getting the optimum aerodynamics at both the cruise and take-off conditions. This is particularly difficult because the operation and the requirements of an open rotor are very different at cruise compared to takeoff. This paper uses CFD results to explore the impact of various design changes on the cruise and take-off flow-fields. The paper then considers how a given open rotor design is best operated at take-off to minimise noise whilst maintaining high thrust. The main findings are that various design modifications can be applied to control the flow features that lead to lost efficiency at cruise and increased noise emission at take-off. A breakdown of the lost power terms from CFD solutions demonstrates how developments in open rotor design have led to reduced aerodynamic losses. At take-off, the operating point of the open rotor should be set such that the non-dimensional lift is as high as possible, without causing significant flow separation. This can be achieved through suitable amounts of re-pitch and speed up applied to a design. Comparisons with fully three-dimensional CFD show that the amount of re-pitch required can be determined using simplified methods such as two-dimensional CFD and a Blade Element Method.This is the accepted manuscript. The final published version is available at http://aerosociety.com/News/Publications/Aero-Journal/Online/2522/How-to-improve-open-rotor-aerodynamics-at-cruise-and-takeoff

Comparison of predicted properties of Ekofisk oils based on Crude Assay data - Evaluation of the predicted behaviour of satellites relative to previous studies.

ConocoPhillips Skandinavia ASpublishedVersio

Assessing the Potential to Detect Oil Spills In and Under Snow Using Airborne Ground-Penetrating Radar

With recent increased interest in oil and gas exploration and development in the Arctic comes increased potential for an accidental hydrocarbon release into the cryosphere, including within and at the base of snow. There is a critical need to develop effective and reliable methods for detecting such spills. Numerical modeling shows that ground-penetrating radar (GPR) is sensitive to the presence of oil in the snow pack over a broad range of snow densities and oil types. Oil spills from the surface drain through the snow by the mechanisms of unsaturated flow and form geometrically complex distributions that are controlled by snow stratigraphy. These complex distributions generate an irregular pattern of radar reflections that can be differentiated from natural snow stratigraphy, but in many cases, interpretation will not be straightforward. Oil located at the base of the snow tends to reduce the impedance contrast with the underlying ice or soil substrate resulting in anomalously low-amplitude radar reflections. Results of a controlled field experiment using a helicopter- borne, 1000-MHz GPR system showed that a 2-cm-thick oil film trapped between snow and sea ice was detected based on a 51% decrease in reflection strength. This is the first reported test of GPR for the problem of oil detection in and under snow. Results indicate that GPR has the potential to become a robust tool that can substantially improve oil spill characterization and remediation

Masse og elite i den romerske republikk

publishedVersio

Subsurface oil releases - Verification of dispersant effectiveness under high pressure

The main objective with this project was to study possible pressure dependency of droplet formation in case of a subsea blow out of oil and the effectiveness of subsea dispersant injection (SSDI). The droplet sizes documented by the SINTEF Silhouette Camera from comparable experiments (nozzle, oil type, flow rates, injection techniques and dispersant product) at ambient conditions (5 meters depth) and high pressure conditions (175 bar or 1750 meters depth) show no significant difference in droplet sizes as a function of pressure. This lack of a pressure effect was observed for both formation of large droplets from untreated oil and formation of smaller droplets by dispersant injection (1 and 2% dispersant dosage). This strongly indicates that SSDI effectiveness is not significantly influenced by hydrostatic pressure. These experiments were performed using stabilized dead oil without gas. Experiments with recombined oil & natura! gas ("live oil") were performed in a study later in 2015 (Brandvik et al., 2016b ).The American Petroleum Institute - API JITF 03publishedVersio

PERTUNJUKAN KESENIAN TERBANG DI KECAMATAN CIATER KABUPATEN SUBANG DAN BENTUK PELESTARIANNYA SEBAGAI BAHAN AJAR PELATIHAN EKSTRAKURIKULER DI SMA

Logita Embang. 2105 “Pertunjukan Kesenian Terbang dan Bentuk Pelestariannya Sebagai Bahan Ajar Pelatihan Ekstrakurikuler Di SMA” Sekolah Pasca Sarjana UPI. Latar belakang: keberadaan pertunjukan kesenian terbang asli yang hampir tidak diminati oleh generasi muda yang beranggapan merupakan kesenian yang bertradisi lama. Masalah penelitian: Bagaimana bentuk pertunjukan kesenian terbang? Bagaimana struktur teks yang terkandung dalam lagu-lagu? Bagaimana ko-teks dan konteks dan fungsi pada pertunjukan kesenian terbang? Bagaimana bentuk pelestarian di SMA? Tujuan dari penelitian: mendeskripsikan pertunjukan kesenian terbang, menyajikan ancangan buku panduan pelatihan ekstrakurikuler di SMA. Teori yang digunakan: teori kebudayaan, tradisi lisan, bentuk dan struktur teks, kajian semantik, bunyi dan teori isi tradisi lisan. Penelitian ini menggunakan metode deskriptif kualitatif. Teknik pengumpulan data: teknik observasi partisipatif, wawancara, dan dokumentasi. Instrumen penelitian: peneliti sendiri dan dibantu dengan pedoman wawancara, observasi, catatan lapangan, tape recorder, dan kamera. Sumber datanya: pertunjukan kesenian terbang, teks lagu-lagu dan konteks. Analisis data dan pembahasan mengenai pertunjukan kesenian terbang, bentuk, analisis struktur semantik dan formula bunyi, ko-teks dan konteks dari lagu-lagu pertunjukan kesenian terbang, Teks lagu-lagu dalam pertunjukan kesenian terbang memiliki struktur semantik yang beragam. Formula bunyinya berupa pengulangan bunyi kata, baik dalam baris, maupun antar baris dengan irama yang dinamis. Konteks dari pertunjukan kesenian terbang ini tidak terikat oleh ruang dan waktu, namun harus mempertimbangkan suasana. Fungsi dari pertunjukan kesenian terbang selain sebagai penghibur juga sebagai unsur pendidikan, pranata kehidupan sosial, fungsi keagamaan. Upaya pelestarian dari pertunjukan kesenian terbang, yaitu melalui pembuatan bahan ajar berupa ancangan buku panduan pelatihan kegiatan ekstrakurikuler di SMA.----------Logita Embang. 2015 “Arts Terbang Performance and Instructional Material As a preservation From Extracurricular Training in School”. Post Graduate of UPI. Background: Young generations are not interested in existence of the original art terbang performance, they thought that it is old tradition. The research problem: how is form of art terbang performance? How the structure of the text contained in the songs? How co-text and context of the function of to show art terbang? What are the forms of preservation in high school? The purpose of the research: to describe art terbang performance, presenting definition guidebook extracurricular training in high school. The used theory: the theory of culture, oral traditions, the shape and structure of the text, the study of semantics, the sound and content of the theory of oral tradition. This research used qualitative descriptive method. Data collection techniques: technique of participant observation, interviews, and documentation. Instrument of the research: the researchers themselves and assisted with interview, observation, field notes, tape recorder, and camera. Source of data: art terbang performance of songs and context. Data analysis and discussion of art terbang performance, to analyze the shape, structure, semantic, and sound formula, co-text and context of art performance songs terbang. Text songs of art terbang performance have a diverse semantic structure. Formula repetition of sound such as the sound of the word, both in rows with a dynamic rhythm. Context of art terbang performance is not bound by the cast and the time, but must consider the atmosphere. The function of the art terbang performance as an entertainer also other than as a component of education, social life institution, a religious function. Conservation effort of art terbang performance is through making material definition guide book training extracurricular in high school

Large-scale basin testing to simulate realistic oil droplet distributions from subsea release of oil and the effect of subsea dispersant injection

Small-scale experiments performed at SINTEF, Norway in 2011–12 led to the development of a modified Weber scaling algorithm. The algorithm predicts initial oil droplet sizes (d50) from a subsea oil and gas blowout. It was quickly implemented in a high number of operational oil spill models used to predict fate and effect of subsea oil releases both in academia and in the oil industry. This paper presents experimental data from large-scale experiments generating oil droplet data in a more realistic multi-millimeter size range for a subsea blow-out. This new data shows a very high correlation with predictions from the modified Weber scaling algorithm both for untreated oil and oil treated by dispersant injection. This finding is opposed to earlier studies predicting significantly smaller droplets, using a similar approach for estimating droplet sizes, but with calibration coefficients that we mean are not representative of the turbulence present in such releases.publishedVersio