Experimental Investigation of the Flow past a Submarine at Angle of Drift

Bridges, David H.; Blanton, James N.; Brewer, Wesley; Park, Joel T.

doi:10.2514/2.1915

Cited by 21 publications

(10 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One near-term objective should be to evaluate the sail as a wall mounted wing in a wind tunnel. 6. Because sail performance as a control surface appears to have exceeded pretest prediction, a re-examination was made of the numerical procedure for modeling CC characteristics at extremely low aspect ratios (less than 2) where, for conventional wings at least, additional lift (beyond linear theory) arises due to the effects of lateral edge vortex flow.…”

Section: Subject Termsmentioning

confidence: 99%

Initial Experimental Evaluation of a Circulation Controlled Sail on a Submersible Vehicle for Enhanced Maneuverability

Imber¹,

Rogers²,

Abramson³

2007

View full text Add to dashboard Cite

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE ABSTRACTThe potential for the sail (bridge fairwater) of a submerged vehicle to serve as an on-demand auxiliary maneuvering control surface was experimentally investigated in a wind tunnel. The sail used circulation (lift) control in the form of mass ejection from Coanda-effect trailing edge region slots. The sail was mounted on, and tested in conjunction with, an exploratory submarine hull design. Test results show that the side force developed by circulation control equaled the side force produced by yawing the fully appended hull by 10 deg, a substantial turning diameter reduction effect. This benefit was present over the tested yaw angle range of +30 deg. Associated yaw moments are in the favorable direction of turning the hull into the turn. Roll moment increments were lower than expected due to a counter-roll effect produced by the pressure field acting on the relatively flat hull topside. For side force and yaw moment, the data indicated that the body-sail interaction effects were negligible at zero angle of hull pitch and yaw (no crossflow). For a 10-deg noseup pitch at zero drift angle, the body reacted to sail circulation by developing an in-plane side force equal to that produced by the circulation of the sail; conversely, at 10 deg nosedown, the body contribution reversed direction so that the net side force was one-half of that at zero pitch. Out-of-plane forces at angles of drift (yaw) were generally not adversely impacted by sail lift augmentation, for a given level of net vehicle side force. Slot flow rate requirements for various operational conditions, and near-term development plans, are discussed. With the successful outcome of this demonstration of a lift augmented sail, it is recommended that systematic maneuvering simulations be conducted to quantify the specific benefits of a circulation controlled sail on naval vessels of interest. ii SUMMARY Circulation control (CC) is a proven technique for producing very high lift forces from a planar surface, independent of flow incidence angle, without moving parts on the surface, and is readily varied by throttling pumped flow to the Coa...

show abstract

Section: Subject Termsmentioning

confidence: 99%

Initial Experimental Evaluation of a Circulation Controlled Sail on a Submersible Vehicle for Enhanced Maneuverability

Imber¹,

Rogers²,

Abramson³

2007

View full text Add to dashboard Cite

show abstract

“…Earlier measurements were performed with a submarine model 5495 for Bridges, et al [10]. The model length was 6.92 m (22.7 ft), and diameter 0.623 m (2.04 ft).…”

Section: Tunnel Velocity Long Term Temporal Stabilitymentioning

confidence: 99%

“…The submarine model was model 5495, which is the same one described in Bridges, et al [10] but with a propeller. For these examples, the speed changes were between zero (zero pump rotation) and 2.5 m/s ( 8.3 ft/s) and between zero and 5 m/s (16.4 ft/s).…”

Section: An Example Of Deceleration Is Shown Inmentioning

confidence: 99%

“…Contour plots of the axial and vertical velocity components are presented in (10,30, and 50 ft/s), respectively. The dimensions of the survey regions were, typically, 900 by 2,200 mm (2.95 by 7.22 ft) with a spatial resolution of 100 mm wide by 150 mm high (3.9 by 5.9 in), or the cross-sectional area of the survey was 22 % of the test section cross-sectional area.…”

Section: Velocity Non-uniformitymentioning

confidence: 99%

See 1 more Smart Citation

Hydrodynamic Performance of the Large Cavitation Channel (LCC)

Park

Cutbirth

Brewer

2003

Volume 2: Symposia, Parts A, B, and C

Self Cite

View full text Add to dashboard Cite

This page intentionally left blank. UNCLASSIFIED REPORT DOCUMENTATION PAGEForm Approved Public reporting burden for this collection of information is estimated to average 1 hour per response, including the lime for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of infomiation. Send comnnents regarding this burden estimate or any other aspect of this collection of information, including suggestions for reduong this burden to Department of Defense, Washington Headquarters Services, Directorate for Infomiation Operations and Reports (0704-0188), 1215 Jefferson Davis Highway. Suite 1204, Ariington. VA 22202-4302 Respondents should be awaiB that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid 0MB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) PERFORMING ORGANIZATION NAME{S) AND ADDRESS(ES) AND ADDRESS(ES)Naval Surface Warfare Center Carderock Division, Code 54 9500 Macarthur Boulevard West Bethesda, MD 20817-5700 SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION /AVAILABILITY STATEMENTApproved for public release. Distribution unlimited. SUPPLEMENTARY NOTES ABSTRACTThe U. S. Navy William B. Morgan Large Cavitation Channel (LCC) in Memphis, Tennessee, is the world's largest water tunnel. This report is a comprehensive documentation of its hydrodynamic performance. Three key characteristics of tunnel velocity were measured: temporal stability, spatial uniformity, and turbulence. Temporal stability and spatial uniformity were measured by laser Doppler anemometer (LDA), while the turbulence was measured with a conical hot-film and constant temperature anemomometer (CTA). The velocity stability at a single point for run times greater than 2 hours was measured as +/-0.15 % at the 95 % confidence level for velocities from 0.5 to 18 m/s. The spatial non-uniformity for the axial velocity component was +/-0.34 to +/-0.60 % for velocities from 3 to 16 m/s. The nonuniformity in the vertical velocity was nominally 2 %. The turbulence or relative turbulence intensity, which is the commonly reported performance characteristic for water tunnels, was measured as 0.2 to 0.5 % depending on tunnel velocity. Additional information includes calibration of the LDA and CTA, test section velocity as a function of pump speed, acceleration of the test section velocity, velocity spectra, and color contour plots of the axial and vertical components for velocity uniformity.

show abstract

“…When a submarine manoeuvres, a complex three-dimensional separation can occur over the body, which can lead to strong streamwise-oriented vortices in the wake, and such vortices can have an important effect on the forces and moments acting on the submarine (Han & Patel 1979;Lloyd & Campbell 1986;Chesnakas & Simpson 1997;Bridges et al 2003;Gregory, Joubert & Chong 2004;Karlsson & Fureby 2009;Hess et al 2010). For a body of revolution in pitch, similar vortices ('body vortices') are formed by the roll-up of the boundary layer due to azimuthal pressure gradients, and this formation process is illustrated in figure 1 for a simplified model of a submarine.…”

mentioning

confidence: 99%

Asymmetries in the wake of a submarine model in pitch

2015

View full text Add to dashboard Cite

Detailed velocity measurements in the wake of a body of revolution are reported for pitch angles up to 12 • , over an unprecedented range of Reynolds numbers (2.4 × 10 6 Re L 30 × 10 6 ). The body of revolution, an idealized submarine shape (DARPA SUBOFF), is mounted using a support that mimics a semi-infinite sail. The wake measurements at all pitch angles and Reynolds numbers reveal the presence of a pair of streamwise vortices of unequal strengths which tend to rotate around each other as they evolve downstream. Various attempts to perturb the upstream conditions on the body had no significant impact on the relative strength of the vortices. In addition, two different models, tested in two different wind tunnels, show similar asymmetries, and we propose that wake asymmetry appears to be a robust feature of this flow, a result previously only seen for sharp-nosed bodies at high angles of attack. It is also shown that the wake behaviour for x/D > 5, in terms of the streamwise mean velocity and turbulence intensity distributions, appears to become invariant with Reynolds number for Re L > 4.8 × 10 6 .

show abstract

Experimental Investigation of the Flow past a Submarine at Angle of Drift

Cited by 21 publications

References 6 publications

Initial Experimental Evaluation of a Circulation Controlled Sail on a Submersible Vehicle for Enhanced Maneuverability

Initial Experimental Evaluation of a Circulation Controlled Sail on a Submersible Vehicle for Enhanced Maneuverability

Hydrodynamic Performance of the Large Cavitation Channel (LCC)

Asymmetries in the wake of a submarine model in pitch

Contact Info

Product

Resources

About