Statement_of_Work.docx

STATEMENT OF WORK FOR

SPECIAL STUDIES FOR WPC 154 HULL PRESSURE FATIGUE LOADING EVALUATIONS

CONTENTS

1. INTRODUCTION

1.1 The US Coast Guard SFLC ESD has been involved in a number of structural analysis efforts requiring limiting load prediction using hydrodynamic load estimation and simulation programs. The hydrodynamic pressure and load calculations are used to determine the fatigue life of patrol boats and cutters in efforts to provide operator guidance and manage the structural integrity through the remaining service life of the hull structure.

1.2 The objective of this effort is to use hydrodynamic models WPC 154 hull for use in fatigue strength analysis and determine the sensitivity of factors influencing the pressure calculations to be applied to structural models.

2. REFERENCE MATERIAL

2.1 The Tasks of this project require information about the WPC 154 hull form and operational parameters.

3. SCOPE OF WORK – The work shall be accomplished through the following tasks.

3.1 Task 1 - Review literature on loading predictions for WPC 154 bow bottom hull form and speed. Both bow loading from waves and local impacts contributing to fatigue loading shall be considered. Approaches included in the review shall include ABS HSNC, VERES Kf, Wedge drop, and RANS CFD. The review shall include oblique and asymmetric hull bow bottom loading. Review literature on approaches for predicting propeller loading in a seaway as a validation case with prior WPC 154 CFD analysis conducted by the contractor. Prepare a summary Power Point presentation report on findings. Coordinate a conference call kick off meeting with the USCG.

3.2 Task 2 – Predict WPC 154 bow bottom pressure using existing WPC 154 models and the RANS CFD approach in head and bow quartering seas and compare to ABS HSNC loads predictions and VERES Kf approach. Provide recommendations for implementing the VERES Kf approach based on the comparisons. Provide a Power Point presentation with summary comparing loading predictions from the CFD, ABS HSNC and VERES approaches. Attend one meeting in Baltimore MD and one meeting in Lockport LA to discuss the tasking progress.

3.3 Task 3 – Use VERES Kf approach with recommended improvements from tasks 1 and 2 to predict pressure loading history on WPC 154 bow bottom structure. Two wave height probability distributions and two operational profiles to be provided by the USCG. Using VERES, evaluate the influence of short crested seas on calculates pressure histogram. Provide pressure load histograms in Excel (MS) format.

3.4 Task 4 – Use RANS CFD approach and existing CFD models of the WPC 154 to predict propeller pressures on the hull to include effects of seaway loading in seaway and operational profiles provided. Evaluate pressure superposition approaches to limit the number of CFD simulations. Provide pressure load histograms in Excel (MS) format.

3.5 Task 5 – Prepare draft instrumentation plan for measuring structural response to bow hydrodynamic pressures and propeller induced pressures on the hull structure. Emphasis shall be placed on measuring hull strain and inferring hull pressures from the strategically located strain measurements. Identify additional testing requirements and instrumentation in coordination with USCG. Test plan shall include both dedicated trials with wave buoy and long term planning. Prepare an estimated scope of effort for conducting the testing. Provide a letter report with the instrumentation plan outline. Attend a test planning meeting with SFLC ESD in Baltimore MD.

3.6 Task 6 – Prepare final report (MS Word), CFD simulation videos (mp3) and Power Point slides (MS Power Point) with results of Tasks 1 through 4. Present results to USCG in Baltimore MD and Lockport LA.

4. DELIVERABLES AND SCHEDULE

DELIVERABLE SCHEDULE

Task 1 Literature Review – 4 weeks ACA Task 2 Pressure Prediction Comparisons – 8 weeks ACA Task 3 VERES Pressure Histogram Predictions – 12 weeks ACA Task 4 Propeller and Seaway Histograms – 18 weeks ACA Task 5 Full Scale Test Planning – 22 weeks ACA Task 6 Final Report – 26 weeks ACA

5. QUALITY ASSURANCE

5.1 The government reserves the right to witness the validation procedures and validation processes of any part of the project development at whatever site such action is taking place.

5.2 The government will review the contents and format of the deliverables in their entirety prior to issuing approval.

6. SECURITY CLEARANCE

6.1 This work is not classified. No security clearance is required.

7. USE OF GOVERNMENT FURNISHED MATERIAL

7.1 Government furnished material and information referenced in 2.0 shall be used for the delivery order only and shall not be used or disseminated for any other purpose.

8. NOTES

8.1 DELIVERY DESTINATION – All items to be delivered under this work statement shall be delivered to the SFLC-ESD technical point of contact, Mr. Karl Stambaugh, with a documenting cover letter at the following address:

For each deliverable a copy of the cover letter shall be provided directly to the Contracting Officer at the following address:

8.2 RIGHTS IN DATA – All data regardless of form or medium are considered to be solely the property of the US Coast Guard and shall not be released without the written consent of the US Coast Guard.